자릿수 지정에 의한 콤마 삽입

 
var result, 
    pattern,
    comma;
 
commna = function (value, len) {
 
    len = len ? len : 3;
    value = value.toString();
    pattern = new RegExp('(^[+-]?\\d+)(\\d{' + len + '})');
 
    while (pattern.test(value)) {
 
        value = value.replace(pattern, '$1' + ',' + '$2');
    }
 
    return value;
}
 
result = comma(123456789, 4);
show(result);