工作笔记-千分位分割

//千分位分割
function toThousands(num) {
    var result = '', counter = 0;
    num = (num || 0).toString();
    for (var i = num.length - 1; i >= 0; i--) {
        counter++;
        result = num.charAt(i) + result;
        if (!(counter % 3) && i != 0) { result = ',' + result; }
    }
    return result;
}

function renderNum(num){
    var cur_num = null;
    var string_num = (num||0).toString();
    var spot_index = string_num.indexOf('.');

    if(spot_index == -1){
        cur_num = toThousands(num);
    }else{
        var cur_spot_num = string_num.substring(spot_index);
        num = string_num.substring(0,spot_index);
        cur_num = toThousands(num);
        cur_num = cur_num+cur_spot_num;
    }

    return cur_num
}

renderNum(1234.45);