封装一个转换成千分符的函数

function test(str){var h = a.length%3;var arr = [];var inum = 0;var tem = []if(h!=0){var atrhead = str.substring(0,h)arr.push(atrhead)}var strleft = str.substring(h);for(var i =0,len = strleft.length;i <len;i++){inum++;tem +=strleft[i];if(inum ==3&&tem){arr.push(tem);inum = 0;tem = ''}}return "千分符"+ arr.join(',')}alert(test(1234567))  //1,234,567