code: function each(source, iterator) {
          if (source instanceof Array) {
              for (var i = 0, len = source.length; i < len; i++) {
                  if (iterator(source[i], i) === false) {
                      break;
                  }
              }
          }
      }
docs: 循环遍历数组集合
  
  @inner
  @param {Array} source 数组源
  @param {function(Array,Number):boolean} iterator 遍历函数