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JavaScript is the programming language of the web. It can calculate, manipulate and validate data. It can update and change both HTML and CSS.
One of many JavaScript HTML methods is getElementById(). The example below "finds" an HTML element (with id="demo"), and changes the element content (innerHTML) to "Hello JavaScript":
document.getElementById("demo").innerHTML = "Hello JavaScript";JavaScript accepts both double and single quotes:
document.getElementById('demo').innerHTML = 'Hello JavaScript';In this example JavaScript changes the value of the src (source) attribute of an <img> tag:
JavaScript Can Change HTML Styles (CSS) Changing the style of an HTML element, is a variant of changing an HTML attribute:
document.getElementById("demo").style.fontSize = "35px";Hiding HTML elements can be done by changing the display style:
document.getElementById("demo").style.display = "none";Showing hidden HTML elements can also be done by changing the display style:
document.getElementById("demo").style.display = "block";Java are two completely different languages, both in concept and design. JavaScript was invented by Brendan Eich in 1995, and became an ECMA standard in 1997.
Formula
ECMA - 262 is the official name of the standard. ECMAScript is the official name of the language.See all JavaScript Versions »