To get a pseudo-random number between 0 and 1, use the Math.random() method in JavaScript.
Example
You can try to run the following code to get a pseudo-random number between 0 and 1 −
<html>
<head>
<title>JavaScript Math random() Method</title>
</head>
<body>
<script>
var value = Math.random( );
document.write("First Value : " + value );
value = Math.random( );
document.write("<br />Second Value : " + value );
</script>
</body>
</html>