js实现金额千分位逗号分割函数

var thousandBitSeparator = function(num){

          var decimal = String(num).split('.')[1] || '';//小数部分

          var tempArr = [];

          var revNumArr = String(num).split('.')[0].split("").reverse();//倒序

          for (i in revNumArr){

            tempArr.push(revNumArr[i]);

            if((i+1)%3 === 0 && i != revNumArr.length-1){

              tempArr.push(',');

            }

          }

          var zs = tempArr.reverse().join('');//整数部分

          return decimal?zs+'.'+decimal:zs;

 }