一些比较便捷的js操作

1. 便捷的取整
   a. var a = 1.2; console.log(~~a);//2
   b. var a = 1.2|0; console.log(a);//2
   c.var a =1.2>>0;console.log(a);//2

2.将字符串转换成数字
a. var a = '22' ;console.log(+a);//22
b. var a = '22'; console.log(parseFloat(a));//22
c. var a = '22';console.log(parseInt(a));//22
d. var a = '22';console.loh(Number(a));//22

3.将数字转化成金钱格式 1234567890 –> 1,234,567,890
var test1 = '1234567890'
var format = test1.replace(/\B(?=(\d{3})+(?!\d))/g, ',')
console.log(format) // 1,234,567,890

4.取数组中的最大值与最小值
var numbers = [5, 458 , 120 , -215 , 228 , 400 , 122205, -85411];
var maxInNumbers = Math.max.apply(Math, numbers);
var minInNumbers = Math.min.apply(Math, numbers);
console.log(maxInNumbers ，minInNumbers )//122205,-85411

5.数组去重
var arr = [1,2,3,1,3,1,1,1,2];
console.log([... new Set[...arr]])

6.快速创建数组
console.log([...new Array(10).keys()])