JavaScript

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JavaScript

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JavaScript is the programming language of HTML and the Web.

JavaScript is easy to learn.

JavaScript and Java are completely different languages, both in concept and design.

JavaScript was invented by Brendan Eich in 1995, and became an ECMA standard in 1997. ECMA-262 is the official name of the standard. ECMAScript is the official name of the language.

Why Study JavaScript?

JavaScript is one of the 3 languages all web developers must learn:

1. HTML to define the content of web pages
2. CSS to specify the layout of web pages
3. JavaScript to program the behavior of web pages

Web pages are not the only place where JavaScript is used. Many desktop and server programs use JavaScript. Node.js is the best known. Some databases, like MongoDB and CouchDB, also use JavaScript as their programming language.

JavaScript Can Change HTML Content

One of many JavaScript HTML methods is getElementById().

document.getElementById("demo").innerHTML = "Hello JavaScript";

JavaScript accepts both double and single quotes:

document.getElementById('demo').innerHTML = 'Hello JavaScript';

JavaScript Can Change HTML Attribute Values

JavaScript Can Change HTML Styles (CSS)

document.getElementById("demo").style.fontSize = "35px";

JavaScript Can Hide HTML Elements

document.getElementById("demo").style.display = "none";

JavaScript Can Show HTML Elements

Showing hidden HTML elements can also be done by changing the display style:

document.getElementById("demo").style.display = "block";

You don't have to get or download JavaScript.
JavaScript is already running in your browser on your computer, on your tablet, and on your smart-phone. Free to use for everyone.

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