1. Math.abs() 获取绝对值
Math.abs(-13) = 13
2. Math.round() 表示四舍五入
var a1 = 3.14;
var a2 = 8.58;
var a3 = -16.13;
var a4 = -19.85;
var r1 = Math.round(a1);
var r2 = Math.round(a2);
var r3 = Math.round(a3);
var r4 = Math.round(a4);
3. Math.ceil() and Math.floor() 向上取整和向下取整
console.log(Math.ceil(12.03));
console.log(Math.ceil(12.92));
console.log(Math.floor(12.3));
console.log(Math.floor(12.9));
var b1 = 3.14;
var b2 = 8.58;
var b3 = -16.13;
var b4 = -16.85;
var b5 = -16.5;
var c1 = Math.ceil(b1);
var c2 = Math.ceil(b2);
var c3 = Math.ceil(b3);
var c4 = Math.ceil(b4);
var c5 = Math.ceil(b5);
var c6 = Math.ceil(b6);
var c1 = 3.1415926;
var c2 = 18.58;
var c3 = -15.23;
var c4 = -16.85;
var c5 = -16.5;
var c6 = 16.5;
var f1 = Math.floor(c1);
var f2 = Math.floor(c2);
var f3 = Math.floor(c3);
var f4 = Math.floor(c4);
var f5 = Math.floor(c5);
var f6 = Math.floor(c6);
4. Math.random() 取[0,1)的随机小数
console.log(parseInt(Math.random()*10));
console.log(parseInt(Math.random()*10+1));
Math.round(Math.random()*(m-n)+n)
5. Math.max() and Max.min() 获取一组数据中的最大值和最小值
console.log(Math.max(10,1,9,100,200,45,78));
console.log(Math.min(10,1,9,100,200,45,78));
6. Math.pow() and Math.sqrt()
Math.pow(5,2) = 25;
Math.sqrt(25) = 5;