内置对象Math
<script>
console.log(Math.pow(2, 3)); //2的3次方
console.log(Math.floor(3.14)); //向下取整 3
console.log(Math.ceil(3.14)); //向上取整 4
console.log(Math.round(3.4)); //4舍5入 3
console.log(Math.round(3.5));//4舍5入 4
console.log(Math.abs(-1)); //绝对值
console.log(Math.max(10, 234, 46, 34, 23, 5)); //最大值
console.log(Math.min(10, 234, 46, 34, 23, 5)); //最小值
//随机数
// Math.random()//0到1之间的饿小数[0,1)
console.log(Math.round(Math.random() * 100)); //0到100之间的随机整数
// Math.round(Math.random() * (max - min)) + min
console.log(Math.round(Math.random() * 20) + 30);
</script>