code: function sortBy(arr, prop, desc) {
      var props = [],
          ret = [],
          i = 0,
          len = arr.length;
      if (typeof prop == 'string') {
          for (; i < len; i++) {
              var oI = arr[i];
              (props[i] = new String(oI && oI[prop] || ''))._obj = oI;
          }
      } else if (typeof prop == 'function') {
          for (; i < len; i++) {
              var _oI = arr[i];
              (props[i] = new String(_oI && prop(_oI) || ''))._obj = _oI;
          }
      } else {
          throw '参数类型错误';
      }
      props.sort();
      for (i = 0; i < len; i++) {
          ret[i] = props[i]._obj;
      }
      if (desc) ret.reverse();
      return ret;
  }
docs: /*
  快速排序，按某个属性，或按“获取排序依据的函数”，来排序.
  @method soryBy
  @static
  @param {array} arr 待处理数组
  @param {string|function} prop 排序依据属性，获取
  @param {boolean} desc 降序
  @return {array} 返回排序后的新数组