text: 'use strict';
  
  /**
   * 字符串补零
   * @param num 要格式化的数值
   * @param len 补零后的文本长度，默认为 2
   * @returns 返回格式化后的时间文本
   * @example
   * ```
   * padZero(2) => "02"
   * padZero(245, 6) => "000245"
   * padZero('7') => "07"
   * ```
   * @author Amery
   * @version v0.2.0
   * @since v0.1.0
   */
  function padZero(num, len) {
      if (len === void 0) { len = 2; }
      var str = num.toString();
      var rl = len - str.length;
      var rs = '';
      while (rl > 0) {
          rs += 0;
          rl--;
      }
      return rs + str;
  }
  
  module.exports = padZero;
  