「快速排序」按某个属性或按“获取排序依据的函数”排序

/*
 * 快速排序，按某个属性，或按“获取排序依据的函数”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
 */
function soryBy(arr, prop, desc) {
  var props = [],
    ret = [],
    i = 0,
    oI,
    len = arr.length;
  if (typeof prop == 'string') {
    for (; i < len; i++) {
      oI = arr[i];
      (props[i] = new String((oI && oI[prop]) || ''))._obj = oI;
    }
  } else if (typeof prop == 'function') {
    for (; i < len; i++) {
      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;
}
export default soryBy;