JavaScript HTML DOM Animation

Learn to create HTML animations using JavaScript.


A Basic Web Page

To demonstrate how to create HTML animations with JavaScript, we will use a simple web page:

Example

<!DOCTYPE html>
<html>
<body><h1>My First JavaScript Animation</h1><div id=”animation”>My animation will go here</div></body>
</html>

Try it Yourself »


Create an Animation Container

All animations should be relative to a container element.

Example

<div id =”container”>
<div id =”animate”>My animation will go here</div>
</div>

Style the Elements

The container element should be created with style = “position: relative”.

The animation element should be created with style = “position: absolute”.

Example

#container {
width: 400px;
height: 400px;
position: relative;
background: yellow;
}
#animate {
width: 50px;
height: 50px;
position: absolute;
background: red;
}

Try it Yourself »

Animation Code

JavaScript animations are done by programming gradual changes in an element’s style.

The changes are called by a timer. When the timer interval is small, the animation looks continuous.

The basic code is:

Example

var id = setInterval(frame, 5);

function frame() {
if (/* test for finished */) {
clearInterval(id);
} else {
/* code to change the element style */
}
}


Create the Animation Using JavaScript

Example

function myMove() {
var elem = document.getElementById(“animate”);
var pos = 0;
var id = setInterval(frame, 5);
function frame() {
if (pos == 350) {
clearInterval(id);
} else {
pos++;
elem.style.top = pos + ‘px’;
elem.style.left = pos + ‘px’;
}
}
}

Try it Yourself »