The document summarizes key elements of JavaScript grammar including variables, operators, expressions, statements, objects, functions, and methods. It provides examples and definitions of each element and notes that JavaScript code uses these elements to make assignments, compare values, and execute sections of code.
The document discusses different approaches to object-oriented programming in JavaScript, including classical and prototypal inheritance, constructor functions, and the prototype property. It also covers topics like pseudoclassical patterns, parasitic inheritance, private methods, and debugging and performance techniques.
This document discusses how to analyze programs for efficiency. It explains that programs should be analyzed both before and after implementation to estimate things like computation time and storage requirements. Key aspects to consider include the number of times loops and statements will be executed, how algorithms and data structures are implemented, and how the program's performance compares to alternatives. An example program for computing the nth Fibonacci number is provided to illustrate some of these concepts.
The document discusses JavaScript functions as first-class objects that can be passed as arguments, returned from other functions, and stored in variables. It explains that functions can be defined using function declarations or function expressions. Function declarations are hoisted to the top of their scope, while function expressions must be assigned to variables. Immediately invoked function expressions (IIFEs) allow defining anonymous functions that execute right away, protecting private variables from polluting the global scope.
$scope - plays a crucial role in gluing the controllers, data & views in AngularJS. Apart from root scope that created by default with ng-app, various child scopes can be created.
Let's see in detail the crucial methods that scope play with.
This document provides an overview of functions in JavaScript. It discusses functions as objects that have a [[Call]] property allowing them to be executed. It describes function declarations vs expressions and how declarations are hoisted. Functions can be treated as values that can be assigned to variables or passed as arguments. Parameters and the arguments object are covered. The document also discusses mimicking function overloading, using functions as object methods, and how the this keyword works differently depending on how a function is called using call, apply, or bind.
A small presentation I developed that introduces lambda expressions and many of the common LINQ extension methods for a group of developers that were less familiar with these concepts.
Scala is a multi-paradigm programming language that blends object-oriented and functional programming. It is designed to express common programming patterns in a concise, elegant, and type-safe way. Scala runs on the Java Virtual Machine and interoperates seamlessly with Java, but also integrates concepts from languages such as Haskell, ML and Ruby. Some key features of Scala include support for functional programming, a static type system with type inference, pattern matching, actors and immutable data structures.
This document discusses objects and classes in Visual Basic. It defines an object as a combination of code and data that can be treated as a unit. A class is described as a template from which objects are created. Key concepts covered include encapsulation, inheritance, polymorphism, object variables, properties, methods, events, collections, and how to create and use custom class modules to define new objects.
The document discusses different approaches to object-oriented programming in JavaScript, including classical and prototypal inheritance, constructor functions, and the prototype property. It also covers topics like pseudoclassical patterns, parasitic inheritance, private methods, and debugging and performance techniques.
This document discusses how to analyze programs for efficiency. It explains that programs should be analyzed both before and after implementation to estimate things like computation time and storage requirements. Key aspects to consider include the number of times loops and statements will be executed, how algorithms and data structures are implemented, and how the program's performance compares to alternatives. An example program for computing the nth Fibonacci number is provided to illustrate some of these concepts.
The document discusses JavaScript functions as first-class objects that can be passed as arguments, returned from other functions, and stored in variables. It explains that functions can be defined using function declarations or function expressions. Function declarations are hoisted to the top of their scope, while function expressions must be assigned to variables. Immediately invoked function expressions (IIFEs) allow defining anonymous functions that execute right away, protecting private variables from polluting the global scope.
$scope - plays a crucial role in gluing the controllers, data & views in AngularJS. Apart from root scope that created by default with ng-app, various child scopes can be created.
Let's see in detail the crucial methods that scope play with.
This document provides an overview of functions in JavaScript. It discusses functions as objects that have a [[Call]] property allowing them to be executed. It describes function declarations vs expressions and how declarations are hoisted. Functions can be treated as values that can be assigned to variables or passed as arguments. Parameters and the arguments object are covered. The document also discusses mimicking function overloading, using functions as object methods, and how the this keyword works differently depending on how a function is called using call, apply, or bind.
A small presentation I developed that introduces lambda expressions and many of the common LINQ extension methods for a group of developers that were less familiar with these concepts.
Scala is a multi-paradigm programming language that blends object-oriented and functional programming. It is designed to express common programming patterns in a concise, elegant, and type-safe way. Scala runs on the Java Virtual Machine and interoperates seamlessly with Java, but also integrates concepts from languages such as Haskell, ML and Ruby. Some key features of Scala include support for functional programming, a static type system with type inference, pattern matching, actors and immutable data structures.
This document discusses objects and classes in Visual Basic. It defines an object as a combination of code and data that can be treated as a unit. A class is described as a template from which objects are created. Key concepts covered include encapsulation, inheritance, polymorphism, object variables, properties, methods, events, collections, and how to create and use custom class modules to define new objects.
Functional programming is a paradigm which concentrates on computing results rather than on performing actions. That is, when you call a function, the only significant effect that the function has is usually to compute a value and return it.
This document discusses pattern matching in Scala. [1] Case classes allow for convenient pattern matching by adding methods like toString and equals. [2] Pattern matching uses match expressions to select alternatives based on patterns. Common patterns include wildcards, constants, variables, constructor patterns for case classes, sequences, tuples, and typed patterns. Patterns can also be used in variable definitions and for expressions.
A JavaScript function is a block of code designed to perform a particular task.
Why Functions?
You can reuse code: Define the code once, and use it many times. You can use the same code many times with different arguments, to produce different results.
It contains basic fundamental of class, object, method overloading, constructor, destructor, visibility, acess specifier, Methods, overloading, clonning of objects etc. are covered here.
Kindly look at it and give your comments to improve it as good as possible ways.
Basic XML Processing In Scala
XML is a form of semi-structured data that organizes content into a tree structure. Scala allows XML to be written as literals and represents XML data as labeled trees. Important classes for processing XML include Node, Text, and NodeSeq. XML can be taken apart in Scala by extracting text using the text method, extracting sub-elements using \ or \\, and extracting attributes using @.
JavaScript variables hold values and are declared with var. Variable names are case sensitive and must begin with a letter or underscore. Variables can hold numbers, strings, Booleans, objects, and null values. Arrays are objects that hold multiple values in a single variable. Functions are blocks of code that perform tasks and are executed by events or calls. Objects store related data and functions to represent self-contained entities.
C# is a great programming language for modern development. Like any language, however, there are parts of the language and BCL that can trip you up if you have invalid assumptions as to what is going on behind the scenes. This presentation discusses a few of these pitfalls and how to avoid them.
Ruby provides several looping structures like for, while, and until loops. Blocks are nameless code segments that can be passed to methods. Procs allow blocks to be treated like objects that are bound to local variables. Lambdas are similar to procs but differ in how they handle parameters and return values. Modules and classes both allow extending behavior but modules cannot be instantiated while classes can.
JavaScript - Chapter 9 - TypeConversion and Regular Expressions WebStackAcademy
This document provides an overview of type conversion and regular expressions in JavaScript. It discusses how JavaScript variables can be converted between different data types either automatically or using functions. It covers converting between numbers, strings, booleans, and dates. It also provides an introduction to regular expressions including patterns, modifiers, and examples of using regular expression methods like exec(), test(), search(), split(), and replace() on strings. The document includes exercises for readers to practice these concepts.
The document discusses various concepts related to functions in Python including defining functions, passing arguments, default arguments, arbitrary argument lists, lambda expressions, function annotations, and documentation strings. Functions provide modularity and code reusability. Arguments can be passed by value or reference and default values are evaluated once. Keyword, arbitrary and unpacked arguments allow flexible calling. Lambda expressions define small anonymous functions. Annotations provide type metadata and docstrings document functions.
Implicit conversions and parameters allow interoperability between types in Scala. Implicit conversions define how one type can be converted to another type, and are governed by rules around marking, scope, ambiguity, and precedence. The compiler tries to insert implicit conversions in three places: to match an expected type, to convert a receiver before a method selection, and to provide missing implicit parameters. Debugging implicits involves explicitly writing out conversions to see where errors occur.
The document provides information on functions in C++. It defines a function as a self-contained block of code that performs a specific task. The key points made include:
1. Functions have a name, return type, arguments, and body of code. They may be library functions or user-defined.
2. Functions are declared with a prototype and defined with a body. They are called by passing arguments.
3. Functions return a value using the return statement. Default return type is int.
4. Functions can have default arguments, be inline to reduce overhead, or be overloaded based on parameters. Recursion and passing objects are also discussed.
Scala supports first-class functions that can be passed as arguments to other functions or stored in variables. Functions can be defined as method members or as anonymous function literals. Function literals allow defining unnamed functions inline. Functions in Scala support closures, where functions can close over variables in the enclosing scope. This allows functions to access variables that are not passed in as arguments. The document discusses various ways to define functions in Scala including local functions, function literals, partially applied functions, and repeated parameters.
This document provides an overview of functional JavaScript concepts including: type system, primitive values, objects, inheritance, functions, closures, pure functions, higher order functions, composition, currying/partial application, and functional techniques like filter, map and reduce. It recommends resources for learning more about functional programming in JavaScript like libraries, books, and workshops.
This document discusses JavaScript basics including its history, variable types, statements, and best practices to avoid coding horrors. It notes that JavaScript was originally meant for popups and has evolved with AJAX and Node.js. It recommends using simple quotes, JSON, and functions for consistency. For statements, it suggests formatting like if statements with brackets and spaces. It also advises splitting files, using namespaces, and keeping line lengths under 250 characters.
Functions in Scala allow dividing programs into smaller, manageable pieces that perform specific tasks. Some key features of functions in Scala include local functions defined inside other functions, first-class functions that can be passed as arguments, partially applied functions, closures that close over variables from outer scopes, and repeated/variable length parameters indicated with an asterisk. Tail recursion makes recursive functions more efficient by ensuring the recursive call is the last operation.
JavaScript allows dynamic programming capabilities to be added to web pages. It is a lightweight scripting language executed in web browsers that is case sensitive. JavaScript code can be embedded directly in HTML pages between <script> tags or placed in external .js files. Code in the HTML body will execute as the page loads while code in the header is executed when called by functions in the body. Common events that can trigger JavaScript code include onload, onsubmit, onmouseover and onchange.
This document provides an overview of JavaScript basics including variables, data types, operators, conditional statements, loops, functions, arrays, and error handling. It explains JavaScript syntax, how to include JavaScript code in HTML pages, and commonly used statements like if/else, switch case, while and for loops. It also covers JavaScript functions, returning values from functions, and printing pages. The document describes JavaScript strings and array objects, and their associated methods. Finally, it discusses different types of errors in JavaScript like syntax errors, runtime errors, and logical errors.
This document provides an introduction to JavaScript, including its uses, differences from Java, and how code is structured in HTML documents. It outlines objectives like learning operators, loops, functions, objects, event handlers and forms. It also covers JavaScript variables and data types, statements and operators, control structures like conditional statements and loops, and statements like break and continue. The overall purpose is to teach the basics of JavaScript programming.
PHP has special data types like resources and NULL. Functions like var_dump(), gettype(), and settype() can output or change a variable's type. Operators like arithmetic, comparison, logical, and assignment are used to produce values from expressions. Constants are defined with define() and cannot change unlike variables.
Functional programming is a paradigm which concentrates on computing results rather than on performing actions. That is, when you call a function, the only significant effect that the function has is usually to compute a value and return it.
This document discusses pattern matching in Scala. [1] Case classes allow for convenient pattern matching by adding methods like toString and equals. [2] Pattern matching uses match expressions to select alternatives based on patterns. Common patterns include wildcards, constants, variables, constructor patterns for case classes, sequences, tuples, and typed patterns. Patterns can also be used in variable definitions and for expressions.
A JavaScript function is a block of code designed to perform a particular task.
Why Functions?
You can reuse code: Define the code once, and use it many times. You can use the same code many times with different arguments, to produce different results.
It contains basic fundamental of class, object, method overloading, constructor, destructor, visibility, acess specifier, Methods, overloading, clonning of objects etc. are covered here.
Kindly look at it and give your comments to improve it as good as possible ways.
Basic XML Processing In Scala
XML is a form of semi-structured data that organizes content into a tree structure. Scala allows XML to be written as literals and represents XML data as labeled trees. Important classes for processing XML include Node, Text, and NodeSeq. XML can be taken apart in Scala by extracting text using the text method, extracting sub-elements using \ or \\, and extracting attributes using @.
JavaScript variables hold values and are declared with var. Variable names are case sensitive and must begin with a letter or underscore. Variables can hold numbers, strings, Booleans, objects, and null values. Arrays are objects that hold multiple values in a single variable. Functions are blocks of code that perform tasks and are executed by events or calls. Objects store related data and functions to represent self-contained entities.
C# is a great programming language for modern development. Like any language, however, there are parts of the language and BCL that can trip you up if you have invalid assumptions as to what is going on behind the scenes. This presentation discusses a few of these pitfalls and how to avoid them.
Ruby provides several looping structures like for, while, and until loops. Blocks are nameless code segments that can be passed to methods. Procs allow blocks to be treated like objects that are bound to local variables. Lambdas are similar to procs but differ in how they handle parameters and return values. Modules and classes both allow extending behavior but modules cannot be instantiated while classes can.
JavaScript - Chapter 9 - TypeConversion and Regular Expressions WebStackAcademy
This document provides an overview of type conversion and regular expressions in JavaScript. It discusses how JavaScript variables can be converted between different data types either automatically or using functions. It covers converting between numbers, strings, booleans, and dates. It also provides an introduction to regular expressions including patterns, modifiers, and examples of using regular expression methods like exec(), test(), search(), split(), and replace() on strings. The document includes exercises for readers to practice these concepts.
The document discusses various concepts related to functions in Python including defining functions, passing arguments, default arguments, arbitrary argument lists, lambda expressions, function annotations, and documentation strings. Functions provide modularity and code reusability. Arguments can be passed by value or reference and default values are evaluated once. Keyword, arbitrary and unpacked arguments allow flexible calling. Lambda expressions define small anonymous functions. Annotations provide type metadata and docstrings document functions.
Implicit conversions and parameters allow interoperability between types in Scala. Implicit conversions define how one type can be converted to another type, and are governed by rules around marking, scope, ambiguity, and precedence. The compiler tries to insert implicit conversions in three places: to match an expected type, to convert a receiver before a method selection, and to provide missing implicit parameters. Debugging implicits involves explicitly writing out conversions to see where errors occur.
The document provides information on functions in C++. It defines a function as a self-contained block of code that performs a specific task. The key points made include:
1. Functions have a name, return type, arguments, and body of code. They may be library functions or user-defined.
2. Functions are declared with a prototype and defined with a body. They are called by passing arguments.
3. Functions return a value using the return statement. Default return type is int.
4. Functions can have default arguments, be inline to reduce overhead, or be overloaded based on parameters. Recursion and passing objects are also discussed.
Scala supports first-class functions that can be passed as arguments to other functions or stored in variables. Functions can be defined as method members or as anonymous function literals. Function literals allow defining unnamed functions inline. Functions in Scala support closures, where functions can close over variables in the enclosing scope. This allows functions to access variables that are not passed in as arguments. The document discusses various ways to define functions in Scala including local functions, function literals, partially applied functions, and repeated parameters.
This document provides an overview of functional JavaScript concepts including: type system, primitive values, objects, inheritance, functions, closures, pure functions, higher order functions, composition, currying/partial application, and functional techniques like filter, map and reduce. It recommends resources for learning more about functional programming in JavaScript like libraries, books, and workshops.
This document discusses JavaScript basics including its history, variable types, statements, and best practices to avoid coding horrors. It notes that JavaScript was originally meant for popups and has evolved with AJAX and Node.js. It recommends using simple quotes, JSON, and functions for consistency. For statements, it suggests formatting like if statements with brackets and spaces. It also advises splitting files, using namespaces, and keeping line lengths under 250 characters.
Functions in Scala allow dividing programs into smaller, manageable pieces that perform specific tasks. Some key features of functions in Scala include local functions defined inside other functions, first-class functions that can be passed as arguments, partially applied functions, closures that close over variables from outer scopes, and repeated/variable length parameters indicated with an asterisk. Tail recursion makes recursive functions more efficient by ensuring the recursive call is the last operation.
JavaScript allows dynamic programming capabilities to be added to web pages. It is a lightweight scripting language executed in web browsers that is case sensitive. JavaScript code can be embedded directly in HTML pages between <script> tags or placed in external .js files. Code in the HTML body will execute as the page loads while code in the header is executed when called by functions in the body. Common events that can trigger JavaScript code include onload, onsubmit, onmouseover and onchange.
This document provides an overview of JavaScript basics including variables, data types, operators, conditional statements, loops, functions, arrays, and error handling. It explains JavaScript syntax, how to include JavaScript code in HTML pages, and commonly used statements like if/else, switch case, while and for loops. It also covers JavaScript functions, returning values from functions, and printing pages. The document describes JavaScript strings and array objects, and their associated methods. Finally, it discusses different types of errors in JavaScript like syntax errors, runtime errors, and logical errors.
This document provides an introduction to JavaScript, including its uses, differences from Java, and how code is structured in HTML documents. It outlines objectives like learning operators, loops, functions, objects, event handlers and forms. It also covers JavaScript variables and data types, statements and operators, control structures like conditional statements and loops, and statements like break and continue. The overall purpose is to teach the basics of JavaScript programming.
PHP has special data types like resources and NULL. Functions like var_dump(), gettype(), and settype() can output or change a variable's type. Operators like arithmetic, comparison, logical, and assignment are used to produce values from expressions. Constants are defined with define() and cannot change unlike variables.
This chapter discusses:
1. Program flow control and statements like conditionals and loops that alter normal linear execution.
2. Conditional statements like if/else that allow choosing which statement executes based on a boolean condition.
3. Repetition statements like while and for loops that repeatedly execute a statement as long as/for as long as a condition is true.
Operators are elements in C# that are applied to operands in expressions or statements. Unary operators take one operand, like increment (++), while binary operators take two operands, such as arithmetic operators (+, -, *, /). The conditional operator (?:) is the sole ternary operator, taking three operands. Some common operators are assignment (=), arithmetic, comparison, conditional (&&, ||), ternary (?:), and null coalescing (??). Operator precedence and associativity determine the order of evaluation in expressions with multiple operators. Parentheses can be used to override precedence.
Operators are symbols that tell the compiler to perform mathematical, logical, or other operations on variables and constants. There are several types of operators including arithmetic, unary, assignment, relational, logical, ternary, bitwise, and shift operators. Arithmetic operators represent basic math operations like addition, subtraction, multiplication, and division. Unary operators operate on a single operand, like increment and decrement operators. Assignment operators assign values, relational operators compare values, and logical operators combine conditional tests.
JavaScript is a client-side scripting language that allows web pages to become interactive and dynamic. It can update and modify the content of an HTML page without needing to reload the page. JavaScript code can be embedded directly in HTML pages or placed in separate .js files. Common uses of JavaScript include validating form input, detecting the visitor's browser, creating cookies, and adding interactivity to HTML elements like buttons and links.
This document provides an overview of JavaScript concepts and features. It introduces JavaScript, its uses, basic syntax like variables, operators, and popup boxes. It also covers conditional statements, loops, functions, arrays, objects like Date and Math objects, regular expressions, and cookies. The document is intended as an introduction to JavaScript for learning its basic concepts.
Java defines several categories of operators: arithmetic, bitwise, relational, logical, and additional special operators. The increment and decrement operators ++ and -- increase or decrease a variable by 1. Relational operators determine the relationship between two operands and return a boolean. Control statements like if-else and switch allow a program to select or loop execution paths. Parentheses can be used to alter operator precedence or clarify complex expressions.
This document provides an introduction to the Java programming language. It discusses Java's evolution and history from 1991 to present. It also covers Java fundamentals including data types, operators, decision making and looping constructs, classes and objects, arrays and strings. The document is intended as an overview of the major topics and features in Java.
Unit 1-scalar expressions and control structuressana mateen
The document discusses scalar expressions and control structures in Perl programming. It covers arithmetic, string, comparison, logical and conditional operators. It also covers control flow structures like if/else, loops (while, until, do-while, for), and loop refinements (last, next, redo). Scalar variables can be combined with operators to form expressions, and control structures allow conditional and repetitive execution of code blocks.
JavaScript is a scripting language used for web pages that is loosely based on Java. It is built into modern browsers. This document provides an introduction and overview of JavaScript, including its syntax, data types, variables, operators, and control structures like if/else statements and loops. It describes how to write basic JavaScript scripts and embed them in HTML pages.
Scalar expressions and control structures in perlsana mateen
Scalar expressions in Perl combine data items using operators like arithmetic, string, comparison, and logical operators. Control structures like conditional expressions and loops like while, until, for, and foreach allow repetition and flow control. Blocks enclosed in curly braces group statements. The if-else, if-elsif conditional expressions and statements execute blocks of code conditionally. Looping constructs iterate until a condition is met or a fixed number of times. Loop refinements like last, next, and redo control flow within loops.
Esoft Metro Campus - Diploma in Web Engineering - (Module V) Programming with JavaScript
(Template - Virtusa Corporate)
Contents:
Introduction to JavaScript
What JavaScript Can Do?
Script tag in HTML
Noscript tag in HTML
Your First JavaScript Program
JavaScript Placement in HTML File
JavaScript Syntax
JavaScript Data Types
JavaScript Variables
JavaScript Identifiers
Arithmetic Operators
String Concatenation Operators
Assignment Operators
Comparison Operators
Logical Operators
Bitwise Operators
If Statement
If… Else Statement
If… Else if… Else Statement
Switch Statement
The ? Operator
While Loop
Do While Loop
For Loop
For…in Loop
break Statement
continue Statement
Arrays
Functions
JavaScript Objects
JavaScript Scope
Strings
Regular Expressions
JavaScript Numbers
Math Object
Date and Time
JavaScript Events
Dialog Boxes
Error Handling in JavaScript
JavaScript Forms Validation
JavaScript HTML DOM
JavaScript BOM
This document provides an overview of JavaScript including:
- It is a dynamic programming language that is interpreted and has object-oriented capabilities. It was introduced in Netscape 2.0 in 1995.
- It allows for increased interactivity on webpages through features like validating user input without page reloads and creating rich interfaces.
- It has various data types, variables, operators, and control structures like conditionals and loops.
- It uses objects and object-oriented programming. Common built-in objects include numbers, strings, arrays, dates and more.
- Functions are reusable blocks of code that can be defined and called. Events allow JavaScript to interact with HTML. Regular expressions provide pattern matching capabilities.
This document provides an introduction to JavaScript. It defines JavaScript as a lightweight, interpreted programming language that allows adding interactivity to HTML pages. Some key points covered include:
- JavaScript advantages like less server interaction and immediate feedback.
- JavaScript limitations like not allowing file reading/writing.
- The Document Object Model (DOM) represents the HTML document when loaded into a browser as a document object that provides access to all node objects.
- Common JavaScript operators, conditional statements, and built-in objects like Math, Date, String, and Window are described. Form validation using JavaScript is also discussed.
OCA Java SE 8 Exam Chapter 2 Operators & Statementsİbrahim Kürce
Operators in Java include unary, binary, and ternary operators that perform operations on operands. Binary operators like arithmetic, relational, and logical operators follow an order of precedence unless overridden by parentheses. Statements in Java include if-then, if-then-else, switch, while, do-while, for, and more to control program flow. The if-then statement and if-then-else statement evaluate conditions and execute code blocks conditionally. The switch statement compares a value to multiple case labels and executes the corresponding code block.
The document discusses various programming concepts including variables, constants, operators, and data types. It defines constants as values that do not change during program execution. It describes different types of operators - arithmetic, logical, and relational - and provides examples of their usage. It also covers operator precedence and expressions. The learning objectives are to define constants, explain operators and their usage, and learn how to use relational and logical operators.
The document discusses various types of expressions and operators in PHP. It describes expressions as bits of PHP code that evaluate to a value, including literal values and variables. Operators take operands and perform operations on them, such as arithmetic, comparison, logical, bitwise, and string operators. It provides examples of using different operators in PHP code and explains concepts like operator precedence, associativity, and type casting.
The document discusses agile methodology and its core principles. It defines agile as an incremental, iterative approach that values frequent delivery of working software and responsiveness to change. The document outlines traditional software development models like waterfall and spiral, then introduces the agile manifesto and its emphasis on individuals, collaboration, customer feedback and responding to change. It describes various agile roles, practices like scrum and XP, and the overall process of organizing work into short iterations to deliver working software.
Enterprise Java Beans (EJBs) allow developers to create reusable components (beans) that can be assembled into applications. EJBs provide services like transactions and security so developers can focus on business logic. Beans run under an EJB container that handles method calls and inserts services. There are three types of beans: entity beans represent database rows, session beans represent processes, and message-driven beans consume JMS messages. Session beans can be stateless, with one bean handling multiple clients concurrently without state, or stateful, where each client is assigned its own bean that maintains state.
The document provides study recommendations for an exam, listing key topics to focus on for chapters about XML (DTD, XML Schema, DOM, SAX), servlet lifecycle, JSP elements (directives, scripting elements, action tags), and JDBC. Links are included to slideshare presentations covering each topic. The recipient is asked to forward the information to classmates and wished good luck on the exam.
Enterprise Java Beans (EJBs) allow developers to create reusable components called beans that can be assembled into applications. Beans encapsulate business logic and delegate common services like transactions and security to the application server. EJBs improve code reuse by allowing the same bean functionality to be used across multiple applications without modifying code.
Enterprise Java Beans (EJBs) allow developers to create reusable components called beans that can be assembled into applications. A bean represents some business logic or functionality that can be reused across applications, such as a customer bean that represents a customer in a database. EJBs take code reuse to a new level by allowing whole functionalities to be reused rather than just code. EJBs let developers focus on business logic while the underlying services like transactions and security are handled by the EJB server.
Enterprise Java Beans (EJBs) allow developers to create reusable components called beans that can be assembled into applications. A bean represents some business logic or functionality that can then be used across different programs. EJBs handle transactions, security, and other services for beans so developers can focus on business logic. Beans run under an EJB container that manages method calls and inserts services like transactions. There are three types of beans: entity beans that represent database rows, message-driven beans that consume JMS messages, and session beans for other business processes.
1. A (2,4)-tree is a type of multiway search tree where each node has between 2 and 4 children and all external nodes are at the same depth, maintaining the tree's balanced structure.
2. Insertion of a new key into a (2,4)-tree is done through searching, then inserting the key and splitting overflowed nodes, maintaining the structure properties. Deletion is done by searching, then deleting and fusing or transferring nodes to resolve underflows.
3. Both insertion and deletion take O(logn) time through splitting or fusing a constant number of nodes per operation while searching takes O(logn) time, maintaining the optimal O(logn
The document summarizes 2-3 trees, which are binary search trees where each internal node has either 2 or 3 children. It describes the structure of internal and leaf nodes, and provides algorithms for searching, inserting, and deleting elements in 2-3 trees. Searching follows the structure of the tree to guide the search path. Insertion may split nodes or increase the tree height, while deletion may merge nodes or decrease the height.
The document discusses the different scopes that can be used to store objects and data in JSP and servlet applications - page, request, session, and application. Objects stored in different scopes are accessible from different parts of the application. Data can be stored in these scopes using attributes, which are key-value pairs. The document provides examples of how to store and retrieve attributes using these different scopes in both JSP pages and servlets.
Java Beans are reusable software components that can be visually manipulated in builder tools. They allow developers to write reusable components once and run them anywhere on any Java-enabled platform. Key features of Java Beans include properties, events, persistence, and introspection to allow visual manipulation in builder tools. Customization is also supported to allow customizing a bean's appearance and behavior.
JDBC is a standard API for accessing SQL databases from Java programs. There are four types of JDBC drivers: Type 1 uses JDBC/ODBC bridge, Type 2 uses platform-specific APIs, Type 3 is 100% Java using network protocol, and Type 4 is also 100% Java and most efficient. Connector/J is a popular Type 4 driver for connecting Java to MySQL. To connect, import necessary classes, register the driver, get a connection, then create statements to execute queries or updates.
This document provides an overview of DOM and SAX, two common XML APIs in Java. It describes the key differences between DOM and SAX, including that DOM builds an in-memory tree representation, while SAX parses the XML as a stream of events. The document also provides code examples for using SAX to parse XML and extract data, and examples of how to access and manipulate DOM trees after parsing XML.
XML documents must follow certain formatting rules to be considered well-formed. They must have a single root element with matching start and end tags for all other elements. Attribute values must be enclosed in quotes. Well-formed XML documents can be represented as a tree structure with a root node containing child nodes, some of which may themselves contain child nodes. The fundamental unit of XML is the element, which can have attributes and content.
The document discusses the building blocks of XML documents including elements, attributes, entities, PCDATA, and CDATA. It also covers how each component is declared in a DTD including element declarations, attribute declarations, and restrictions on content and occurrence.
An XML schema defines the structure and elements of an XML document. It is an XML-based alternative to DTDs that allows defining element types, attributes, data types, defaults and restrictions. Schemas support namespaces, data types, extensibility and are written in XML, allowing the use of XML tools. Complex elements can contain child elements, text or both.
Java Server Pages (JSP) is a technology that allows developers to create dynamic web applications using Java code embedded in HTML pages. JSP pages are compiled into Java servlets, allowing dynamic content to be generated. JSP supports the use of scripting elements like expressions, scriptlets, and declarations directly in HTML pages to add dynamic functionality. Common elements like directives, actions, and standard tags provide functionality like including pages, passing parameters, and abstracting common patterns.
Request dispatching allows one servlet to forward a request to another servlet, JSP, or HTML page for further processing. This is done using a RequestDispatcher object, which can be obtained from the servlet context or request object. The RequestDispatcher's forward() method dispatches the request without the client's knowledge, maintaining request parameters, while include() dispatches and includes the response in the original response without changing headers.
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HTTP is the protocol used to deliver web pages and other resources over the internet. It uses a client-server model, where an HTTP client like a web browser sends requests to an HTTP server, which responds with the requested resources. Requests and responses consist of request/response lines followed by headers and an optional message body. Common request methods are GET and POST, while common response status codes include 200 for success and 404 for "not found". Web servers listen on port 80 by default to receive HTTP requests and send responses. Servlets are Java programs that extend the capabilities of web servers by allowing applications to be executed on the server-side. Servlets provide advantages over CGI scripts like improved performance through caching and platform independence through their Java
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Java Script Language Tutorial
1. JAVA SCRIPT LANGUAGE
JavaScript code, much like other programming languages, is made up of statements which
serve to make assignments, compare values, and execute other sections of code. By and
large, programmers will already be familiar with JavaScript's usage of variables, operators,
and statements. Below is a chart summarizing the main elements of JavaScript grammar.
Following, we will look at each element in detail.
Variables Labels which refer to a changeable value.
Example: total may be possess a value of 100.
Operators Actors which can be used to calculate or compare values.
Example: Two values may be summed using the addition operator (+); total+tax
Example: Two values may be compared using the greater-than operator (>); total>200
Expressions Any combination of variables, operators, and statements which evaluate
to some result. In English parlance this might be termed a quot;sentencequot; or
even a quot;phrasequot;, in that grammatical elements are combined into a cogent
meaning.
Example: total=100;
Example: if (total>100)
Statements As in English, a statement pulls all grammatical elements together into a
full thought. JavaScript statements may take the form of conditionals,
loops, or object manipulations. It is good form to separate statements by
semicolons, although this is only mandatory if multiple statements reside
on the same line.
Example: if (total>100) {statements;} else {statements;}
Example: while (clicks<10) {statements;}
Objects Containing constructs which possess a set of values, each value reflected
into an individual property of that object. Objects are a critical concept
and feature of JavaScript. A single object may contain many properties,
each property which acts like a variable reflecting a certain value.
JavaScript can reference a large number of quot;built-inquot; objects which refer
to characteristics of a Web document. For instance, the document object
contains properties which reflect the background color of the current
document, its title, and many more. For a fuller explanation of the built-in
objects of JavaScript, see the section on quot;Document Object Modelquot;.
Functions and A JavaScript function is quite similar to a quot;procedurequot; or quot;subroutinequot; in
Methods other programming languages. A function is a discrete set of statements
which perform some action. It may accept incoming values (parameters),
and it may return an outgoing value. A function is quot;calledquot; from a
JavaScript statement to perform its duty. A method is simply a function
which is contained in an object. For instance, a function which closes the
current window, named close(), is part of the window object; thus,
window.close() is known as a method.
2. Operators take one or more variables or values (operands) and return a new value; e.g. the
'+' operator can add two numbers to produce a third. You use operators in expressions to
relate values, whether to perform arithmetic or compare quantities. Operators are divided
into several classes depending on the relation they perform:
arithmetic or computational
Arithmetic operators take numerical values (either literals or variables) as their operands
and return a single numerical value. The standard arithmetic operators are:
+ Addition
- Subtraction
* Multiplication
/ Division
Modulus: the remainder after division;
%
e.g. 10 % 3 yields 1.
Unary increment: this operator only takes one operand. The operand's value is
increased by 1. The value returned depends on whether the ++ operator is
++
placed before or after the operand; e.g. ++x will return the value of x following
the increment whereas x++ will return the value of x prior to the increment.
Unary decrement: this operator only takes one operand. The operand's value is
decreased by 1. The value returned depends on whether the -- operator is placed
--
before or after the operand; e.g. --x will return the value of x following the
decrement whereas x-- will return the value of x prior to the decrement.
- Unary negation: returns the negation of operand.
comparison
A comparison operator compares its operands and returns a logical value based on whether
the comparison is true or not. The operands can be numerical or string values. When used
on string values, the comparisons are based on the standard lexicographical (alphabetic)
ordering.
== quot;Equal toquot; returns true if operands are equal.
3. != quot;Not equal toquot; returns true if operands are not equal.
> quot;Greater thanquot; returns true if left operand is greater than right operand.
quot;Greater than or equal toquot; returns true if left operand is greater than or equal to
>=
right operand.
< quot;Less thanquot; returns true if left operand is less than right operand.
quot;Less than or equal toquot; returns true if left operand is less than or equal to right
<=
operand.
boolean
Boolean operators are typically used to combine multiple comparisons into a conditional
expression. For example, you might want to test whether (total>100) AND (stateTax=true).
A boolean operator takes two operands, each of which is a true or false value, and returns a
true or false result.
&& quot;Andquot; returns true if both operands are true.
|| quot;Orquot; returns true if either operand is true.
! quot;Notquot; returns true if the negation of the operand is true (e.g. the operand is false).
string
Strings can be compared using the comparison operators. Additionally, you can
concatenate strings using the + operator.
quot;dogquot; + quot;bertquot; yields quot;dogbertquot;
assignment
The assignment operator (=) lets you assign a value to a variable. You can assign any value
to a variable, including another variable (whose value will be assigned). Several shorthand
assignment operators allow you to perform an operation and assign its result to a variable
in one step.
= Assigns the value of the righthand operand to the variable on the
left.
Example: total=100;
Example: total=(price+tax+shipping)
+= Adds the value of the righthand operand to the lefthand variable
(also -=, *=, /=) and stores the result in the lefthand variable.
Example: total+=shipping (adds value of shipping to total and assigned
result to total)
4. &= Assigns result of (lefthand operand && righthand operand) to
(also |=) lefthand operand.
special
Several JavaScript operators, rarely used, fall into no particular category. These operators
are summarized below.
Conditional operator Assigns a specified value to a variable if a condition is
true, otherwise assigns an alternate value if condition is
false.
(condition) ? trueVal : falseVal
Example:
preferredPet = (cats > dogs) ? quot;felinesquot; : quot;caninesquot;
If (cats>dogs), preferredPet will be assigned the string
value quot;felines,quot; otherwise it will be assigned quot;caninesquot;.
typeof operand Returns the data type of operand.
Example -- test a variable to determine if it contains a number:
if (typeof total==quot;numberquot;) ...
JAVA SCRIPT STATEMENTS
Statements define the flow of a script, known as quot;program flow.quot; A statement, like a fully
grammatical English sentence, is made up of smaller expressions which, altogether,
evaluate into a cogent meaning. In JavaScript, statements are organized as either
conditionals, loops, object manipulations, and comments.
Good practice suggests that each JavaScript statements should be terminated with a
semicolon (;). This is often not strictly necessary, as a new line also serves to separate
statements, but when multiple statements reside on the same line the semicolon delimiter is
mandatory.
A set of statements that is surrounded by braces is called a block. Blocks of statements are
used, for example, in functions and conditionals.
Normally statements are executed sequentially: x = 1; y = 2; z = x + y; but this can
be altered by some statements which test a condition and branch or loop according to the
result.
Conditionals
5. Conditional statements direct program flow in specified directions depending upon the
outcomes of specified conditions. These tests are a major influence on the order of
execution in a program.
if...else
As seen in many programming languages, if the condition evaluates to true then the block
of statements1 is executed. Optionally, an else clause specifies a block of statements2
which are executed otherwise. You may omit the else clause if there are no statements
which need to be executed if the condition is false.
if (condition)
{ statements1; }
else
{ statements2; }
switch (Netscape & MSIE 4)
Commonly known as a quot;case statement,quot; switch matches an expression with a specified
case, and executes the statements defined for that case. In essence, the switch statement is a
sort of shorthand for combining many implied if statements together.
switch (expression){
case label :
statement;
break;
case label :
statement;
break;
...
default : statement;
}
For example, imagine that you wanted to execute different sets of statements depending on
whether favoritePet was quot;dog,quot; quot;cat,quot; or quot;iguana.quot; Note that the break; statement prevents
any cases below the match from being executed. The default case is matched if none of the
cases match the expression.
switch (favoritePet){
case quot;dogquot; :
statements;
break;
case quot;catquot; :
statements;
break;
case quot;iguanaquot; :
6. statements;
break;
default : statements;
}
Loops
for
The venerable for loop repeatedly cycles through a block of statements until a test
condition is false. Typically, the number of times a loop is repeated depends on a counter.
The JavaScript for syntax incorporates the counter and its increments:
for (initial-statement; test; increment)
{ statements; }
The initial-statement is executed first, and once only. Commonly, this statement is used to
initialize a counter variable. Then the test is applied and if it succeeds then the statements
are executed. The increment is applied to the counter variable and then the loop starts
again. For instance, consider a loop which executes 10 times:
for (i=0; i<10; i++)
{ statements; }
do...while (Netscape & MSIE 4)
Another loop, a do...while statement executes a block of statements repeatedly until a
condition becomes false. Due to its structure, this loop necessarily executes the statement at
least once.
do
{ statements;}
while (condition)
while
In similar fashion as the do...while statement, the while statement executes its statement
block as long as the condition is true. The main difference between while and do...while,
aside from the fact that only while is supported in all JavaScript versions, is that a while
loop may not execute the statements even once if the condition is initially false.
while (condition)
{ statements; }
7. break and continue
Both of these statements may be used to quot;jump the tracksquot; of an iterating loop. When used
within the statement block of a loop, each statement behaves slightly differently:
break Aborts execution of the loop, drops out of loop to the next
statement following the loop.
continue Aborts this single iteration of the loop, returns execution to
the loop control, meaning the condition specified by the
loop statement. Loop may execute again if condition is
still true.
Object manipulation
for...in
The sometimes confusing for...in statement is used to cycle through each property of an
object or each element of an array. The idea is that you may want to execute a statement
block which operates on every property or element.
for (variable in object)
{ statements; }
Imagine, for example, that an object named wine1 has five properties: vineyard, year,
varietal, alcohol, and color. You want to output the value of each property, as if producing
a record from a database.
var record = quot;Wine 1<br><br>quot;
for (var prop in wine1)
{record += prop + quot; = quot; + wine1[prop] + quot;<BR>quot;}
record += quot;<br>quot;
document.write(record)
with
The with statement serves as a sort of shorthand, allowing you to execute a series of
statement who all assume a specified object as the reference. In other words, the object
specified in the with statement is used as the default object whenever a property is
encountered with no object specified.
with (object)
{ statements; }
8. Comments
Despite the fact that comments are purely optional, they can easily be a crucial part of your
program. Comments can explain the action, like a color commentary, which can be a great
help in understanding the code. Whether as a teaching tool or to simply remind yourself
what the code does, comments are best sprinkled liberally throughout a program.
Remember, comments are for humans, so write them that way!
Comments can also be used for debugging -- you can comment quot;outquot; sections of code to
prevent them from being executed. In doing so you may learn more about why a certain
problem is occurring in your program.
Because JavaScript must ignore comments, there is an appropriate syntax for demarcating
text as a comment. For single line comments, simply precede the line with two backslashes.
For multi-line comment blocks, begin the comment with /* and close with */.
//A lonely ol' single line comment
/* A dense thicket of commentary, spanning many captivating lines
of explanation and intrigue. */
JS FUNCTIONS
A function groups together a set of statements under a named subroutine. This allows you
to conveniently quot;callquot; the function whenever its action is required. Functions are a
fundamental building block of most JavaScript programs, so you'll become quite familiar
with their use. Before you can call on a function, of course, you must first create it. We can
break down the use of functions, then, into two logical categories: defining functions and
calling functions.
defining functions
The function definition is a statement which describes the function: its name, any values
(known as quot;argumentsquot;) which it accepts incoming, and the statements of which the
function is comprised.
function funcName(argument1,argument2,etc)
{ statements; }
A function doesn't necessarily require arguments, in which case you need only write out the
parenthesis; e.g. funcName(). If you do specify arguments, those arguments will be
variables within the function body (the statements which make up the function). The initial
values of those variables will be any values passed on by the function call.
Generally it's best to define the functions for a page in the HEAD portion of a document.
Since the HEAD is loaded first, this guarantees that functions are loaded before the user
9. has a chance to do anything that might call a function. Alternately, some programmers
place all of their functions into a separate file, and include them in a page using the SRC
attribute of the SCRIPT tag. Either way, the key is to load the function definitions before
any code is executed.
Consider, for example, a simple function which outputs an argument to the Web page, as a
bold and blinking message:
function boldblink(message)
{ document.write(quot;<blink><strong>quot;+message+quot;</strong></blink>quot;); }
Some functions may return a value to the calling expression. The following function
accepts two arguments, x and y, and returns the result of x raised to the y power:
function raiseP(x,y)
{ total=1;
for (j=0; j<y; j++)
{ total*=x; }
return total; //result of x raised to y power
}
calling functions
A function waits in the wings until it is called onto the stage. You call a function simply by
specifying its name followed by a parenthetical list of arguments, if any:
clearPage();
boldblink(quot;Call me gaudy!quot;);
Functions which return a result should be called from within an expression:
total=raiseP(2,8);
if (raiseP(tax,2)<100) ...
Quite commonly, JavaScript functions are called from within event handlers
JAVA SCRIPT OBJECTS
An object is a quot;packagequot; of data; a collection of properties (variables) and methods
(functions) all classed under a single name. For example, imagine that there was an object
named car. We could say that the car object possesses several properties: make, model,
year, and color, for example. We might even say that car possesses some methods: go(),
stop(), and reverse(). Although car is obviously fictional, you can see that its properties and
methods all relate to a common theme.
In JavaScript you may create your own objects for storing data. More commonly, though,
you will use the many quot;built-inquot; objects which allow you to work with, manipulate, and
10. access the Web page and Web browser. This set of pre-existing objects is known as the
quot;Document Object Modelquot;.
Document Object Model
Often referred to as the DOM, this object model is a hierarchy of all objects quot;built inquot; to
JavaScript. Most of these objects are directly related to characteristics of the Web page or
browser. The reason we qualify the term quot;built inquot; is because the DOM is technically
separate from JavaScript itself. That is, the JavaScript language specification, standardized
by the ECMA, does not actually specify the nature or specifics of the DOM. Consequently,
Netscape and Microsoft have developed their own individual DOM's which are not entirely
compatible. Additionally, the DOM stands apart from JavaScript because it could
theoretically be accessed by other scripting languages as well.
In summary, then, what we refer to as quot;JavaScriptquot; is actually made up of both JavaScript,
the language, and the DOM, or object model which JavaScript can access. In a future
WDVL article we will take a closer look at the DOM and its current and future role.
Below is a graphical chart illustrating a high-level view of Netscape's DOM. Microsoft's
DOM is actually a superset of Netscape's, and so the chart below actually represents a
subset of Microsoft's own DOM.
11. Reprinted from Netscape's JavaScript Guide
Properties
Access the properties of an object with a simple notation: objectName.propertyName. Both
the object name and property name are case sensitive, so watch your typing. Because a
property is essentially a variable, you can create new properties by simply assigning it a
value. Assuming, for instance, that carObj already exists (we'll learn to create a new object
shortly), you can give it properties named make, model, and year as follows:
carObj.make=quot;Toyotaquot;;
carObj.model=quot;Camryquot;;
carObj.year=1990;
document.write(carObj.year);
A JavaScript object, basically, is an array. If you're familiar with other languages you
probably recognize an array as a collection of values residing within a single named data
structure. You can access an object's properties either using the objectName.propertyName
syntax illustrated above, or by using an array syntax:
carObj[quot;makequot;]=quot;Toyotaquot;;
carObj[quot;modelquot;]=quot;Camryquot;;
document.write(carObj[quot;yearquot;]);
Methods
Unlike a basic data array, an object can also contain functions, which are known as
methods when part of an object. You call a method using the basic syntax:
objectName.methodName(). Any arguments required for the method are passed between
the parentheses, just like a normal function call.
For example, the window object possesses a method named close(), which simply closes
the specified browser window:
window.close();
Creating Objects
Most of the time you will be referencing objects which are built-in to the DOM. However,
you may want to create your own objects for storing data within a JavaScript program.
There are several ways to create a new object, but we'll look at two: creating a direct
instance of an object and creating an object prototype.
12. direct instance of an object
Despite the awkward sound name, a quot;direct instance of an objectquot; simply means creating a
new single object, such as myPetDog:
myPetDog=new Object();
myPetDog.name=quot;Barneyquot;;
myPetDog.breed=quot;beaglequot;;
myPetDog.year=1981;
Assigning a method to your new object is also simple. Assume that you already have coded
a function named woof(), which causes a barking sound to play:
myPetDog.woof=woof;
prototype of an object
Sometimes, you'll want to create a quot;templatequot; or prototype of an object. This does not
create an actual instance of the object, but defines the structure of the object. In the future,
then, you can quickly stamp out a particular instance of the object. Suppose that instead of
myPetDog, you created a prototype object named petDog. This object could then be a
template for a particular pet dog object. First, create a function which defines the petDog
structure:
function petDog(name, breed, year)
{ this.name = name;
this.breed = breed;
this.year = year;
}
Now that the petDog prototype has been set, you can quickly create single instances of a
new object based on the petDog structure:
myPetDog=new petDog(quot;barneyquot;,quot;beaglequot;,1981);
yourPetDog=new petDog(quot;maxquot;,quot;terrierquot;,1990);
EVENT HANDLER
JavaScript programs are typically event-driven. Events are actions that occur on the Web
page, usually as a result of something the user does, although not always. For example, a
button click is an event, as is giving focus to a form element; resizing the page is an event,
as is submitting a form. It is these events which cause JavaScript programs to spring into
13. action. For example, if you move your mouse over this phrase, a message will pop-up,
courtesy of JavaScript.
An event, then, is the action which triggers an event handler. The event handler specifies
which JavaScript code to execute. Often, event handlers are placed within the HTML tag
which creates the object on which the event acts:
<tag attribute1 attribute2 onEventName=quot;javascript code;quot;>
For example, a hyperlink is subject to a MouseOver event, meaning that its event handler
will be triggered when the mouse passes over the link. Therefore, you place the event
handler for a hyperlink's MouseOver inside the A tag:
<a href=quot;quot; onMouseOver=quot;popupFunc();quot;>
The JavaScript which is called by the event handler may be any valid JavaScript code: a
single statement or a series of statements, although most often it is a function call.
The set of all events which may occur, and the particular page elements on which they can
occur, is part of the Document Object Model (DOM), and not JavaScript itself (see the
earlier section quot;Document Object Modelquot;). As a result, Netscape and Microsoft do not
share the exact same set of events, nor are all page elements subject to the same events
between browsers. For example, Internet Explorer 4 supports a MouseOver event for an
image while Navigator 4 does not.
The table below illustrates some of the most commonly used events supported in both
DOM's. Because the DOM's differ in their event support, the following documents are
recommended as an overview of each browser's event support:
Navigator 4: Event Handlers Summary
•
MSIE 4: DHTML Event Summary
•
Common Events
Event
Event Occurs when...
Handler
click User clicks on form element or link onClick
change User changes value of text, textarea, or select element onChange
focus User gives form element input focus onFocus
blur User removes input focus from form element onBlur
14. mouseover User moves mouse pointer over a link or anchor onMouseOver
mouseout User moves mouse pointer off of link or anchor onMouseOut
select User selects form element's input field onSelect
submit User submits a form onSubmit
resize User resizes the browser window onResize
load User loads the page in the Navigator onLoad
unload User exits the page onUnload