js字符串加入千分号

var str = '12345672';
str.replace(/\d{1,3}(?=(\d{3})+$)/g, '$&,');
console.log(str);

var str = '12345672';
var permil = function (str){//字符串加千分号
var iNum = str.length % 3;
var eStr = str.substring(iNum);
var arr = [];
var temp = '';
var iNow = 0;

if (iNum != 0) {
var sStr = str.substring(0,iNum);
arr.push(sStr);
}

for (var i = 0; i < eStr.length; i++) {
iNow ++;
temp += eStr[i];
if (iNow == 3) {
arr.push(temp);
temp = '';
iNow = 0;
}
}
return arr.join(',');
}
console.log(permil(str));

12,345,672