Motivation:
- HTML and CSS only allow for static content
- HTML/CSS do not allow for generating dynamic content that can change based on user input, activity, etc.
- However, recall that the browser has an engine for generating dynamic content using JavaScript
The background of JS:
- Developed at Netscape Communications in mid-1990s as a way of adding dynamic elements to HTML
- Originally known as “LiveScript”; changed to “JavaScript” soon after its release
- Now one of the most popular programming languages in the world
How to use JS:
- JavaScript can be embedded directly in the HTML inside<script> tags and/or using <link> tags to external .js files
- Browsers such as Chrome provide a JavaScript “REPL” console for writing and evaluating code (Can also see output generated by JavaScript in HTML )
- You can also develop JavaScript in a .js file and execute it in a runtime environment such as Node.js
Code example:
Effect:
<!DOCTYPE html>
<html>
<head>
</head>
<body>
This is my first JavaScript web page.
<p>
<script>
document.write('The current date and time is ');
var time = new Date();
document.write(time);
</script>
</body>
</html>
Effect:
This is my first JavaScript web page.
Ref:
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