1.取余数 %
var a=10%3;
//a=1
2.取绝对值 Math.abs()
var a=Math.abs(-102.1);
var b=Math.abs(102.1);
//a=102.1;b=102.1
3.截取小数点后长度并进行四舍五入 toFixed()
var num_1 = new Number(13.53);
alert(num_1.toFixed(1));
alert(num_1.toFixed(0));
//13.5
//14
var num_2 = new Number(13.56);
alert(num_2.toFixed(1));
alert(num_2.toFixed(0));
//13.6
//14
4.取最小值 Math.min()
Math.min(5,7)
Math.min(-3,5)
Math.min(-3,-5)
(Math.min(7.25,7.30)
//结果
//5
//-3
//-5
//7.25
5.取最大值 Math.max()
Math.max(5,7,9)
Math.max(-3,5)
Math.max(-3,-5)
Math.max(7.25,7.30)
//结果
//9
//5
//-3
//7.30
6.指数计数法 和 截取数字固定长度 toPrecision()
var a=1000.25;
alert(a.toPrecision(1))
alert(a.toPrecision(2))
alert(a.toPrecision(4))
alert(a.toPrecision(6))
alert(a.toPrecision(8))
//结果
//1e+3
//1.0e+3
//1000
//1000.25
//1000.2500
7.把一个数字舍入为最接近的整数 round()
Math.round(0.60)
Math.round(0.50)
Math.round(0.49)
Math.round(-4.40)
Math.round(-4.60)
//结果
//1
//1
//0
//-4
//-5
转载：http://www.cnblogs.com/zqzjs/p/4713139.html
