The document provides an introduction to JavaScript functions. It explains that functions allow code to be reused by defining reusable blocks of code called functions. It provides examples of simple functions that check if a number is greater than or equal to 21, and adds additional time to a number of minutes. The document emphasizes that functions are like buttons on a microwave that each serve a specific purpose. It encourages readers to try out functions on their own.
php complete reference with database concepts for beginners is generally useful for those who want to start the career as a php developer. given each and every information right from the scratch to understand for the beginners and students as well. I hope this will help you a lot for the beginners to start the career.
Learn how to write better code. Follow key software development principles like KISS, DRY, YAGNI, and SOLID. Know how to choose better names, structure your code, write methods, and design classes.
JavaScript is a versatile programming language primarily used for building dynamic and interactive web applications. Developed by Netscape Communications Corporation in the mid-1990s, JavaScript has since become one of the most popular programming languages worldwide. Here's a detailed description of JavaScript:
Introduction to JavaScript:
JavaScript is a high-level, interpreted programming language that allows developers to add functionality, interactivity, and behavior to web pages. Unlike server-side languages like PHP or Python, JavaScript is executed on the client-side, meaning it runs within the user's web browser. This enables dynamic manipulation of webpage content without requiring communication with the server.
Slides from a talk I gave about using the Ruby on Rails console (and irb) to develop Web applications. Describes the features of the console, and how you might want to use it.
php complete reference with database concepts for beginners is generally useful for those who want to start the career as a php developer. given each and every information right from the scratch to understand for the beginners and students as well. I hope this will help you a lot for the beginners to start the career.
Learn how to write better code. Follow key software development principles like KISS, DRY, YAGNI, and SOLID. Know how to choose better names, structure your code, write methods, and design classes.
JavaScript is a versatile programming language primarily used for building dynamic and interactive web applications. Developed by Netscape Communications Corporation in the mid-1990s, JavaScript has since become one of the most popular programming languages worldwide. Here's a detailed description of JavaScript:
Introduction to JavaScript:
JavaScript is a high-level, interpreted programming language that allows developers to add functionality, interactivity, and behavior to web pages. Unlike server-side languages like PHP or Python, JavaScript is executed on the client-side, meaning it runs within the user's web browser. This enables dynamic manipulation of webpage content without requiring communication with the server.
Slides from a talk I gave about using the Ruby on Rails console (and irb) to develop Web applications. Describes the features of the console, and how you might want to use it.
4. Speaking in Code
Big Picture: HTML/CSS vs. JavaScript
• HTML/CSS are computer languages that define
content, structure, and how things look
• JavaScript is a programming language where you give
the computer instructions
– Set of directions such as for recipes
5. Speaking in Code
Big Picture: Programming
• Learning JavaScript – programming language
• Widely-applicable concepts
6. Speaking in Code
Programming Language Similarities
• JavaScript
if (x < 10) {
console.log("x is less than 10!");
}
• Ruby
if x < 10
puts "x is less than 10!"
• Python
if x < 10:
print "x is less than 10!"
7. Speaking in Code
Programming Language Similarities
• JavaScript
if (x < 10) {
console.log("x is less than 10!");
}
• Java
if(x < 10)
{
System.out.println("x is less than 10!");
}
8. Speaking in Code
Big Picture: What we’re learning now
• Using JavaScript to tell browser what to do
• “Front-end” language
9. Speaking in Code
Big Picture: How it all fits in (HTML)
<!DOCTYPE html>
<html>
<head>
<title>HTML title</title>
</head>
<body>
<p>paragraph</p>
</body>
</html>
10. Speaking in Code
Big Picture: How it all fits in (CSS)
<!DOCTYPE html>
<html>
<head>
<title>HTML title</title>
<link type="text/css" rel="stylesheet" href="stylesheet.css"/>
</head>
<body>
<p id=“color-me”>paragraph</p>
</body>
</html>
11. Speaking in Code
Big Picture: How it all fits in (JavaScript)
<!DOCTYPE html>
<html>
<head>
<title>HTML title</title>
<link type="text/css" rel="stylesheet" href="stylesheet.css"/>
<script type="text/javascript" src="script.js"></script>
</head>
<body>
<p id=“color-me”>paragraph</p>
</body>
</html>
12. Speaking in Code
JavaScript
• Each line is read one at a time
• Comments
// These won’t be read in JavaScript
• Most lines are ended with ;
– Like a period at the end of a sentence
13. Speaking in Code
JavaScript
• Print to the screen (console)
console.log(‘Hello World’);
console.log(9482301);
• Try it in your browser console
– Right-click -> Inspect Element -> Console
14. Speaking in Code
Recap: Types
• Everything is associated with a type
• Numbers
254
• Strings
“Hi there!”
• Booleans
true
false
15. Speaking in Code
Recap: Types – Strings
• You can concatenate strings
“Brian” + “ Lee”
>> Brian Lee
“1” + “ 1”
>> “11”
16. Speaking in Code
Recap: Conditionals
• Arithmetic expressions compute to a Number
4 * 5;
>> 20
• Conditionals compute to a Boolean
20 > 15;
>> true
13 >= 15;
>> false
18. Speaking in Code
Recap if statements
• Execute code based on a set of conditions
• English: If you are older than 21, then you can drink
• JavaScript: (try in JSbin)
var i = 18;
if ( i >= 21) {
console.log(“you can drink!”);
}else {
console.log(“better wait another year”);
}
19. Speaking in Code
Variables
• Very similar to variables in algebra
• Begin with var to instantiate
var firstName = “Brian”
var lastName = “Lee”
console.log(firstName + “ “ + lastName)
>> “Brian Lee”
• Common practice to camelCase
20. Speaking in Code
Variables
• Should be lowercase first (otherwise Objects)
• Cannot start with numbers, no spaces
var 1stName = “Brian”
var LastName = “Lee”
21. Speaking in Code
Common Gotchas
• Important:
var taxRate = 1.089;
var tax rate = 1.089; //error no spaces between variable names
vartaxRate = 1.089; //error need space between var and variable name
• Not as important
var taxRate = 1.089;
var taxRate = 1.089;
if(10 > 5) { console.log("Hello!"); }
22. Speaking in Code
Indenting
• Similar to the principals for HTML
• Makes it easier for you!
• No set standard, but just stick to it!
var i = 18;
if (i >= 21) {
console.log(‘you can drink!’);
}else {
console.log(‘better wait another year’);
}
23. Speaking in Code
Gotcha’s: Read line by line
• This won’t work:
var cost = 24.99;
var total = cost * taxRate;
var taxRate = 1.089;
24. Speaking in Code
Intro to Functions: Name
• No need to repeat same code
• Set of instructions
var drinking = function(age) {
if (age >= 21) {
console.log(‘you can drink!’);
}else {
console.log(‘better wait another year’);
}
};
drinking(21);
25. Speaking in Code
Intro to Functions: Syntax
• No need to repeat same code
• Set of instructions
var drinking = function(age) {
if (age >= 21) {
console.log(‘you can drink!’);
}else {
console.log(‘better wait another year’);
}
};
drinking(21);
26. Speaking in Code
Intro to Functions: Parameters
• No need to repeat same code
• Set of instructions
var drinking = function(age) {
if (age >= 21) {
console.log(‘you can drink!’);
}else {
console.log(‘better wait another year’);
}
};
drinking(21);
29. Speaking in Code
Functions === Microwave Buttons?
• Each button has a purpose
• Same as a function
var minutes = 5
var addTime = function(minutes, additionalMinutes) {
minutes = minutes + additionalMinutes;
return minutes;
};
addTime(minutes, 10);
>> 15