This document provides an overview of object oriented programming concepts in JavaScript. It discusses how JavaScript supports OOP through prototypes, functions acting as classes, and constructor functions to initialize objects. The document also covers data types in JavaScript, error handling using try/catch blocks, and techniques to improve performance such as reducing DOM access and unnecessary variables. It provides examples of implementing inheritance, abstraction, polymorphism, and other OOP principles in JavaScript.
JavaScript - Chapter 4 - Types and StatementsWebStackAcademy
A computer program is a list of "instructions" to be "executed" by a computer.
In a programming language, these programming instructions are called statements.
A JavaScript program is a list of programming statements.
JavaScript statements are composed of:
Values, Operators, Expressions, Keywords, and Comments.
This statement tells the browser to write "Hello Dolly." inside an HTML element with id="demo":
JavaScript Data Types
JavaScript variables can hold many data types: numbers, strings, objects and more.
In programming, data types is an important concept.
To be able to operate on variables, it is important to know something about the type.
JavaScript - Chapter 4 - Types and StatementsWebStackAcademy
A computer program is a list of "instructions" to be "executed" by a computer.
In a programming language, these programming instructions are called statements.
A JavaScript program is a list of programming statements.
JavaScript statements are composed of:
Values, Operators, Expressions, Keywords, and Comments.
This statement tells the browser to write "Hello Dolly." inside an HTML element with id="demo":
JavaScript Data Types
JavaScript variables can hold many data types: numbers, strings, objects and more.
In programming, data types is an important concept.
To be able to operate on variables, it is important to know something about the type.
JavaScript String:
The String object lets you work with a series of characters; it wraps Javascript's string primitive data type with a number of helper methods.
As JavaScript automatically converts between string primitives and String objects, you can call any of the helper methods of the String object on a string primitive.
JavaScript Arrays:
The Array object lets you store multiple values in a single variable. It stores a fixed-size sequential collection of elements of the same type. An array is used to store a collection of data, but it is often more useful to think of an array as a collection of variables of the same type.
Just a simple intro to typescript.
Most of the contents are of any OO language, hence slide contents are minimal. If anyone need any further help, reach me out - akhil2369492@gmail.com
-Akhil
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.
Angular - Chapter 4 - Data and Event HandlingWebStackAcademy
In Angular , events such as button click or any other sort of events can also be handled very easily. The events get triggered from the html page and are sent across to Angular JS class for further processing.
Data binding is a core concept in Angular and allows to define communication between a component and the DOM, making it very easy to define interactive applications without worrying about pushing and pulling data. There are four forms of data binding and they differ in the way the data is flowing.
Things you should know about Javascript ES5. A programming language that enables you to create dynamically updating content, control multimedia, animate images, and pretty much everything else
JavaScript - Chapter 9 - TypeConversion and Regular Expressions WebStackAcademy
Type Conversion:
JavaScript is loosely typed language and most of the time operators automatically convert a value to the right type but there are also cases when we need to explicitly do type conversions.
While JavaScript provides numerous ways to convert data from one type to another but there are two most common data conversions :
Converting Values to String
Converting Values to Numbers
Regular Expressions:
A regular expression is an object that describes a pattern of characters.
The JavaScript RegExp class represents regular expressions, and both String and RegExp define methods that use regular expressions to perform powerful pattern-matching and search-and-replace functions on text.
Generally speaking, a function is a "subprogram" that can be called by code external (or internal in the case of recursion) to the function. Like the program itself, a function is composed of a sequence of statements called the function body. Values can be passed to a function, and the function will return a value.
In JavaScript, functions are first-class objects, because they can have properties and methods just like any other object. What distinguishes them from other objects is that functions can be called. In brief, they are Function objects.
JavaScript - An Introduction is a beginner's guide to JavaScript. It starts with very basic level and goes to intermediate level. You'll be introduced with every language constructs, Event handling, Form handling and AJAX which is supported by JavaScript with XMLHttpRequest object. This XHR object is discussed in enough detail so that you can understand how the underlying AJAX functionality works in jQuery. At the end it discusses advance concepts and library build on/around JavaScript.
Come see how easy it is to build fast, accurate, and responsive web UIs using the React library. Even if you’ve never written Javascript before, React’s straightforward syntax can get you started with your UI project quickly. In this session, you’ll learn about React’s declarative syntax and state representation, explore some of the basic components that are used to build sophisticated UIs, and leave with a foundational application you can continue to build on.
JavaScript String:
The String object lets you work with a series of characters; it wraps Javascript's string primitive data type with a number of helper methods.
As JavaScript automatically converts between string primitives and String objects, you can call any of the helper methods of the String object on a string primitive.
JavaScript Arrays:
The Array object lets you store multiple values in a single variable. It stores a fixed-size sequential collection of elements of the same type. An array is used to store a collection of data, but it is often more useful to think of an array as a collection of variables of the same type.
Just a simple intro to typescript.
Most of the contents are of any OO language, hence slide contents are minimal. If anyone need any further help, reach me out - akhil2369492@gmail.com
-Akhil
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.
Angular - Chapter 4 - Data and Event HandlingWebStackAcademy
In Angular , events such as button click or any other sort of events can also be handled very easily. The events get triggered from the html page and are sent across to Angular JS class for further processing.
Data binding is a core concept in Angular and allows to define communication between a component and the DOM, making it very easy to define interactive applications without worrying about pushing and pulling data. There are four forms of data binding and they differ in the way the data is flowing.
Things you should know about Javascript ES5. A programming language that enables you to create dynamically updating content, control multimedia, animate images, and pretty much everything else
JavaScript - Chapter 9 - TypeConversion and Regular Expressions WebStackAcademy
Type Conversion:
JavaScript is loosely typed language and most of the time operators automatically convert a value to the right type but there are also cases when we need to explicitly do type conversions.
While JavaScript provides numerous ways to convert data from one type to another but there are two most common data conversions :
Converting Values to String
Converting Values to Numbers
Regular Expressions:
A regular expression is an object that describes a pattern of characters.
The JavaScript RegExp class represents regular expressions, and both String and RegExp define methods that use regular expressions to perform powerful pattern-matching and search-and-replace functions on text.
Generally speaking, a function is a "subprogram" that can be called by code external (or internal in the case of recursion) to the function. Like the program itself, a function is composed of a sequence of statements called the function body. Values can be passed to a function, and the function will return a value.
In JavaScript, functions are first-class objects, because they can have properties and methods just like any other object. What distinguishes them from other objects is that functions can be called. In brief, they are Function objects.
JavaScript - An Introduction is a beginner's guide to JavaScript. It starts with very basic level and goes to intermediate level. You'll be introduced with every language constructs, Event handling, Form handling and AJAX which is supported by JavaScript with XMLHttpRequest object. This XHR object is discussed in enough detail so that you can understand how the underlying AJAX functionality works in jQuery. At the end it discusses advance concepts and library build on/around JavaScript.
Come see how easy it is to build fast, accurate, and responsive web UIs using the React library. Even if you’ve never written Javascript before, React’s straightforward syntax can get you started with your UI project quickly. In this session, you’ll learn about React’s declarative syntax and state representation, explore some of the basic components that are used to build sophisticated UIs, and leave with a foundational application you can continue to build on.
The curious Life of JavaScript - Talk at SI-SE 2015jbandi
My talk about the life of JavaScript, from birth to today.
I went trough the demos and code examples very quickly, rather as a teaser to show how modern JavaScript development might look.
If you are interested in a deep dive into the topic of modern JavaScript development, HTML5, ES6, AngularJS, React, Gulp, Grunt etc, please consider my courses: http://www.ivorycode.com/#schulung
Presentation to the MIT IAP HTML5 Game Development Class on Debugging and Optimizing Javascript, Local storage, Offline Storage and Server side Javascript with Node.js
JavaScript Libraries - Prototype and jQuery
http://www.refresh-events.ca/events/javascript-libraries-jquery-and-prototype/
Refresh Events is proud to present Cameron Westland (bigbangtechnology.com) and Eugene Andruszczenko (32teeth.org) for our first event of 2009. The topic of the evening will be an analysis of Prototype and jQuery, two increasingly popular JavaScript frameworks. Cameron and Eugene will perform deep-dives into Prototype and jQuery (respectively) and examine the benefits and drawbacks of using each language. The goal is not to see which one emerges as the “better language”, but instead to promote the concept of the right tool for the job.
Writing and Testing JavaScript-heavy Web 2.0 apps with JSUnitAlex Chaffee
With the advent of the so-called Web 2.0 platform, more and more applications are using client-side JavaScript for vital features. In fact, some applications are so JS-heavy that they redefine JavaScript as a full-fledged application development language. In this tutorial we discuss some architectural considerations of JS- and AJAX-heavy applications and present in detail our testing framework, with plenty of code examples.
GraphRAG is All You need? LLM & Knowledge GraphGuy Korland
Guy Korland, CEO and Co-founder of FalkorDB, will review two articles on the integration of language models with knowledge graphs.
1. Unifying Large Language Models and Knowledge Graphs: A Roadmap.
https://arxiv.org/abs/2306.08302
2. Microsoft Research's GraphRAG paper and a review paper on various uses of knowledge graphs:
https://www.microsoft.com/en-us/research/blog/graphrag-unlocking-llm-discovery-on-narrative-private-data/
The Art of the Pitch: WordPress Relationships and SalesLaura Byrne
Clients don’t know what they don’t know. What web solutions are right for them? How does WordPress come into the picture? How do you make sure you understand scope and timeline? What do you do if sometime changes?
All these questions and more will be explored as we talk about matching clients’ needs with what your agency offers without pulling teeth or pulling your hair out. Practical tips, and strategies for successful relationship building that leads to closing the deal.
Transcript: Selling digital books in 2024: Insights from industry leaders - T...BookNet Canada
The publishing industry has been selling digital audiobooks and ebooks for over a decade and has found its groove. What’s changed? What has stayed the same? Where do we go from here? Join a group of leading sales peers from across the industry for a conversation about the lessons learned since the popularization of digital books, best practices, digital book supply chain management, and more.
Link to video recording: https://bnctechforum.ca/sessions/selling-digital-books-in-2024-insights-from-industry-leaders/
Presented by BookNet Canada on May 28, 2024, with support from the Department of Canadian Heritage.
Observability Concepts EVERY Developer Should Know -- DeveloperWeek Europe.pdfPaige Cruz
Monitoring and observability aren’t traditionally found in software curriculums and many of us cobble this knowledge together from whatever vendor or ecosystem we were first introduced to and whatever is a part of your current company’s observability stack.
While the dev and ops silo continues to crumble….many organizations still relegate monitoring & observability as the purview of ops, infra and SRE teams. This is a mistake - achieving a highly observable system requires collaboration up and down the stack.
I, a former op, would like to extend an invitation to all application developers to join the observability party will share these foundational concepts to build on:
UiPath Test Automation using UiPath Test Suite series, part 3DianaGray10
Welcome to UiPath Test Automation using UiPath Test Suite series part 3. In this session, we will cover desktop automation along with UI automation.
Topics covered:
UI automation Introduction,
UI automation Sample
Desktop automation flow
Pradeep Chinnala, Senior Consultant Automation Developer @WonderBotz and UiPath MVP
Deepak Rai, Automation Practice Lead, Boundaryless Group and UiPath MVP
Builder.ai Founder Sachin Dev Duggal's Strategic Approach to Create an Innova...Ramesh Iyer
In today's fast-changing business world, Companies that adapt and embrace new ideas often need help to keep up with the competition. However, fostering a culture of innovation takes much work. It takes vision, leadership and willingness to take risks in the right proportion. Sachin Dev Duggal, co-founder of Builder.ai, has perfected the art of this balance, creating a company culture where creativity and growth are nurtured at each stage.
Key Trends Shaping the Future of Infrastructure.pdfCheryl Hung
Keynote at DIGIT West Expo, Glasgow on 29 May 2024.
Cheryl Hung, ochery.com
Sr Director, Infrastructure Ecosystem, Arm.
The key trends across hardware, cloud and open-source; exploring how these areas are likely to mature and develop over the short and long-term, and then considering how organisations can position themselves to adapt and thrive.
Essentials of Automations: Optimizing FME Workflows with ParametersSafe Software
Are you looking to streamline your workflows and boost your projects’ efficiency? Do you find yourself searching for ways to add flexibility and control over your FME workflows? If so, you’re in the right place.
Join us for an insightful dive into the world of FME parameters, a critical element in optimizing workflow efficiency. This webinar marks the beginning of our three-part “Essentials of Automation” series. This first webinar is designed to equip you with the knowledge and skills to utilize parameters effectively: enhancing the flexibility, maintainability, and user control of your FME projects.
Here’s what you’ll gain:
- Essentials of FME Parameters: Understand the pivotal role of parameters, including Reader/Writer, Transformer, User, and FME Flow categories. Discover how they are the key to unlocking automation and optimization within your workflows.
- Practical Applications in FME Form: Delve into key user parameter types including choice, connections, and file URLs. Allow users to control how a workflow runs, making your workflows more reusable. Learn to import values and deliver the best user experience for your workflows while enhancing accuracy.
- Optimization Strategies in FME Flow: Explore the creation and strategic deployment of parameters in FME Flow, including the use of deployment and geometry parameters, to maximize workflow efficiency.
- Pro Tips for Success: Gain insights on parameterizing connections and leveraging new features like Conditional Visibility for clarity and simplicity.
We’ll wrap up with a glimpse into future webinars, followed by a Q&A session to address your specific questions surrounding this topic.
Don’t miss this opportunity to elevate your FME expertise and drive your projects to new heights of efficiency.
Elevating Tactical DDD Patterns Through Object CalisthenicsDorra BARTAGUIZ
After immersing yourself in the blue book and its red counterpart, attending DDD-focused conferences, and applying tactical patterns, you're left with a crucial question: How do I ensure my design is effective? Tactical patterns within Domain-Driven Design (DDD) serve as guiding principles for creating clear and manageable domain models. However, achieving success with these patterns requires additional guidance. Interestingly, we've observed that a set of constraints initially designed for training purposes remarkably aligns with effective pattern implementation, offering a more ‘mechanical’ approach. Let's explore together how Object Calisthenics can elevate the design of your tactical DDD patterns, offering concrete help for those venturing into DDD for the first time!
Generative AI Deep Dive: Advancing from Proof of Concept to ProductionAggregage
Join Maher Hanafi, VP of Engineering at Betterworks, in this new session where he'll share a practical framework to transform Gen AI prototypes into impactful products! He'll delve into the complexities of data collection and management, model selection and optimization, and ensuring security, scalability, and responsible use.
Accelerate your Kubernetes clusters with Varnish CachingThijs Feryn
A presentation about the usage and availability of Varnish on Kubernetes. This talk explores the capabilities of Varnish caching and shows how to use the Varnish Helm chart to deploy it to Kubernetes.
This presentation was delivered at K8SUG Singapore. See https://feryn.eu/presentations/accelerate-your-kubernetes-clusters-with-varnish-caching-k8sug-singapore-28-2024 for more details.
4. JavaScript
JavaScript is a high level, dynamic, untyped, and interpreted programming
language. It has been standardized in the ECMAScript language specification
(European Computer Manufacturers Association).
JavaScript was designed by Brendan Eich.
Speed. Being client-side, JavaScript is very fast because any code functions can be
run immediately instead of having to contact the server and wait for an answer.
JavaScript is very easy to implement. All you need to do is put your code in the
HTML document and tell the browser that it is JavaScript.
JavaScript works on web users’ computers — even when they are offline!
JavaScript allows you to create highly responsive interfaces that improve the user
experience and provide dynamic functionality, without having to wait for the server
to react and show another page.
5. JavaScript
JavaScript can load content into the document if and when the user needs it,
without reloading the entire page — this is commonly referred to as Ajax.
While in the past it was a common argument that JavaScript was a basic language
and was very 'slap dash' with no real foundation; this is no longer the case,
especially with the introduction of high scale web applications and 'adaptations'
such as JSON (JavaScript Object Notation).
List of JavaScript libraries. Ex. Dojo Toolkit, jQuery, midori, MooTools, Prototype
JavaScript Framework, YUI Library
Security Issues – Open to client.
JavaScript rendering varies – Compatibility issue.
6. JavaScript
Programming languages used in most popular websites*
Websites
Popularity (Unique
Visitors)
Front-end
(Client Side)
Back-end (Server Side) Database
Google.com 1,100,000,000JavaScript C, C++, Go,Java, Python BigTable, MariaDB
YouTube.com 1,000,000,000JavaScript C/C++, Python, Java,Go MySQL, BigTable, MariaDB
Facebook.com
900,000,000 JavaScript Hack, PHP, C++, Java, Python,Erlang, D,Xhp MySQL, HBaseCassandra
Yahoo 750,000,000 JavaScript JavaScript, PHP MySQL, PostgreSQL
Amazon.com 500,000,000 JavaScript Java, C++, Perl Oracle Database
Wikipedia.org 475,000,000 JavaScript PHP , Hack MySQL, MariaDB
Twitter.com 290,000,000 JavaScript C++, Java, Scala, Ruby on Rails MySQL
Bing 285,000,000 JavaScript ASP.NET Microsoft SQL Server
eBay.com 285,000,000 JavaScript Java,JavaScript Oracle Database
MSN.com 280,000,000 JavaScript ASP.NET Microsoft SQL Server
Microsoft 270,000,000
Linkedin.com 260,000,000JavaScript Java, JavaScript, Scala Voldemort
Pinterest 250,000,000 JavaScript Django(a Python framework) MySQL, Redis
Ask.com 245,000,000
Wordpress.com 240,000,000 JavaScript PHP MySQL
8. OOPs
Object Oriented programming is a programming style that is associated with the
concept of OBJECTS, having data fields and related member functions.
Concepts of OOPs.
1. Objects
2. Classes
3. Data Abstraction
4. Encapsulation
5. Inheritance
6. Polymorphism
7. Dynamic Binding
Improved software-development productivity.
Improved software maintainability.
Faster development & Lower cost of development.
Object Oriented programs require a lot of work to create.
10. OOPs in JavaScript
JavaScript supports Object Oriented Programming but not in the same way as other
OOP languages(C++, php, Java, etc.) do.
The main difference between JavaScript and the other languages is that, there are
no Classes in JavaScript whereas Classes are very important for creating objects.
However there are ways through which we can simulate the Class concept in
JavaScript.
Another important difference is Data Hiding. There is no access specifier like
(public, private and protected) in JavaScript but we can simulate the concept using
variable scope in functions.
11. OOPs in JavaScript
Object
Any real time entity is considered as an Object. Every Object will have some properties
and functions.
More ways to create objects in JavaScript like:
1)Creating Object through literal
var obj={};
2)Creating with Object.create
var obj= Object.create(null);
3)Creating using new keyword
function Person(){}
var obj=new Person();
12. OOPs in JavaScript
Class
There are no classes in JavaScript as it is Prototype based language. But we can simulate
the class concept using JavaScript functions.
function Person(){
//Properties
this.name=“Forzia";
this.startYear=“2015";
//functions
this.CompInfo=function(){
return this.name +" Says Hi";
}
}
//Creating person instance
var p=new Person();
alert(p.CompInfo());
13. OOPs in JavaScript
Constructor
Actually Constructor is a concept that comes under Classes. Constructor is used to
assign values to the properties of the Class while creating object using new operator.
function Person(name,age){
//Assigning values through constructor
this.name=name;
this.age=age;
//functions
this.sayHi=function(){
return this.name +" Says Hi";
}
}
//Creating person instance
var p=new Person("aravind",23);
alert(p.sayHi());
//Creating Second person instance
var p=new Person("jon",23);
alert(p.sayHi());
14. OOPs in JavaScript
Inheritance (Work around)
Inheritance is a process of getting the properties and function of one class to other
class.
For example let’s consider "Student" Class, here the Student also has the properties of
name and age which has been used in Person class.
So it's much better to acquiring the properties of the Person instead of re-creating the
properties.
Now let’s see how we can do the inheritance concept in JavaScript.
var Person = function (){
this.sayHi=function(){
return " Says Hi"; }
}
//1)Prototype based Inheritance
Student.prototype= new Person();
//2)Inhertance throught Object.create
Student.prototype=Object.create(Person);
var stobj=new Student();
alert(stobj.sayHi());
We can do inheritance in above two ways.
15. OOPs in JavaScript
Abstraction
Abstraction means hiding the inner implementation details and showing only outer
details. To understand Abstraction we need to understand Abstract and Interface
concepts from Java. But we don't have any direct Abstract or Interface in JS.
Ex. In JQuery we will use
$("#ele")
to select select an element with id ele on a web page. Actually this code calls negative
JavaScript code
document.getElementById("ele");
But we don't need to know that we can happy use the $("#ele") without knowing the
inner details of the implementation.
16. OOPs in JavaScript
Polymorphism
The word Polymorphism in OOPs means having more than one form.
function Person(age,weight){
this.age = age;
this.weight = weight;
}
Person.prototype.getInfo = function(){
return "I am " + this.age + " years old " +
"and weighs " + this.weight +" kilo.";
};
function Employee(age,weight,salary){
this.age = age;
this.weight = weight;
this.salary = salary;
}
Employee.prototype = new Person();
Employee.prototype.getInfo = function(){
return "I am " + this.age + " years old " +
"and weighs " + this.weight +" kilo " +
"and earns " + this.salary + " dollar.";
};
var person = new Person(50,90);
var employee = new Employee(43,80,50000);
console.log(person.getInfo());
console.log(employee.getInfo());
17. Data Types In JavaScript
Data Types
• JavaScript variables can hold many data types: numbers, strings, arrays, objects and
more:
var length = 16; // Number
var lastName = "Johnson"; // String
var cars = ["Saab", "Volvo", "BMW"]; // Array
var x = {firstName:"John", lastName:"Doe"}; // Object
• In JavaScript, a variable without a value, has the value undefined. The typeof is also
undefined.
• JavaScript arrays are written with square brackets.
Array items are separated by commas. Ex. var cars = ["Saab", "Volvo", "BMW"];
• JavaScript objects are written with curly braces.
Object properties are written as name:value pairs, separated by commas.
Ex: var person = {firstName:"John", lastName:"Doe", age:50, eyeColor:"blue"};
18. Error Handling In JavaScript
JavaScript try and catch
The try statement allows you to define a block of code to be tested for errors while it is
being executed.
The catch statement allows you to define a block of code to be executed, if an error
occurs in the try block.
Example:
<script>
try {
var aa=name.reaplace(‘m’,’s’);
}
catch(err) {
alert(err.message);
}
</script>
19. Improve Performance in JavaScript
1.Reduce Activity in Loops
Bad:
for (i = 0; i < arr.length; i++) {}
Better:
l = arr.length;
for (i = 0; i < l; i++) {}
2.Reduce DOM Access
Accessing the HTML DOM is very slow, compared to other JavaScript statements.
If you expect to access a DOM element several times, access it once, and use it as a local variable:
obj = document.getElementById("demo");
obj.innerHTML = "Hello";
3.Reduce DOM Size
Keep the number of elements in the HTML DOM small.
This will always improve page loading, and speed up rendering (page display), especially on smaller
devices.
Every attempt to search the DOM (like getElementsByTagName) will benefit from a smaller DOM.
20. Improve Performance in JavaScript
4. Avoid Unnecessary Variables
Don't create new variables if you don't plan to save values.
Often you can replace code like this:
var fullName = firstName + " " + lastName;
document.getElementById("demo").innerHTML = fullName;
With this:
document.getElementById("demo").innerHTML = firstName + " " + lastName
5.Delay JavaScript Loading
Putting your scripts at the bottom of the page body, lets the browser load the page first.
While a script is downloading, the browser will not start any other downloads. In addition all
parsing and rendering activity might be blocked.
An alternative is to use defer="true" in the script tag.
The defer attribute specifies that the script should be executed after the page has finished parsing,
but it only works for external scripts.
6.Avoid Using with
Avoid using the with keyword. It has a negative effect on speed. It also clutters up JavaScript scopes.
The with keyword is not allowed in strict mode.