javascript

Javascript

Javascript Tutorial

JS Introduction
Getting Started
JS Syntax
JS Comments
JS Values
JS Operators
JS Expressions
JS Identifiers
JS Where To
JS Variables
JS Generate Output
JS Program
JS Data Type
JS Events
JS Strings
JS Numbers
JS Conditional Statements
JS Arrays
JS Loops
JS Functions
JS Objects

JavaScript Tutorial

JavaScript is an object-oriented client-side scripting language that helps you build web-based applications. By client side scripting, we speak of the scripts that run on the web browser.

JavaScript helps you add dynamic effects and enhance the interactivity of the web pages by controlling the information sent by the web server.

The development of JavaScript dates back to the mid 1990s by Brendan Eich, an American Computer Programmer. It was initially called LiveScript and was renamed to JavaScript in 1995. It was accepted as ECMA standard in the year 1997. The ECMA (European Computer Manufacturers Association) officially looks after JavaScript.

All the modern web browsers such as Mozilla Firefox, Google Chrome, and Safari support JavaScript.

What can you do using JavaScript?

  • Change the webpage contents by including and eliminating elements
  • Manage transitions and animations
  • Validate user input prior to sending them to the web server
  • Create alert pop-ups to showcase information or warning messages for the users
  • Track events such as mouse click and hover
  • Control the styling and positioning of elements on webpage
  • Conduct tasks depending on the user inputs and showcase the output

Getting Started with JavaScript

How can you add JavaScript to a web page?

There are three methods to add JavaScript in a web page.

  • Embed the JavaScript code between a pair of <script> and </script> tag.
  • Create an external JavaScript file with the .js extension. Load it within the page through the src attribute of the <script> tag.
  • Insert the JavaScript code directly inside an HTML tag using the special tag attributes such as onclick, onmouseover, onkeypress, onload.

Let's discuss these methods in detail

Embed the JavaScript Code: Embed the JavaScript code between a pair of <script> and </script> tag. The <script> tag instructs the web browser to interpret the contained statements as executable script.

Example

.html
<!DOCTYPE html>    
<html lang="en">    
<head>    
<meta charset="UTF-8">
<title>Embedding JavaScript Code</title>
</head>

<body>

<script>
var j = "Introduction to JavaScript";
document.write(j);
</script>

</body>

</html>