JavaScript的Math对象的random方法可以返回一个0-1之间随机数
<!DOCTYPE html>
<html>
<body>
<p id="demo">Click the button to display a random number.</p>
<button onclick="myFunction()">Try it</button>
<script>
function myFunction()
{
document.getElementById("demo").innerHTML=Math.random();
}
</script>
</body>
</html>
