<!DOCTYPE html>
<html>
<head lang="en">
<meta charset="UTF-8">
<title></title>
</head>
<body>
<script>
//
// var num = 1.4;
var num = -0.6;
console.log(Math.abs(num)); //取绝对值
console.log(Math.floor(num)); //向下取整 //向小取
console.log(Math.ceil(num)); //向上取整 //向大取
console.log(Math.round(num)); //四舍五入取整 //正数四舍五入，负数五舍六入
console.log(Math.random()); //随机数0-1
</script>
</body>
</html>
math
