javascript - Angular 循环中的分组和汇总

Question

我的数据格式如下:

[{id: 178, uid: "1", when: "2018-01-17", gingerbread: "75", created_at: "2018-01-..., 
{id: 179, uid: "1", when: "2018-01-17", gingerbread: "32", created_at... }];

如果我想 *ngFor 循环遍历这些对象的数组并根据 when 找到 gingerbread 的总和，有人可以阐明执行此操作的最佳方法好吗？

Answer 1

你可以在 Controller 中做这样的事情:

var myArray = [{id: 178, uid: "1", when: "2018-01-17", gingerbread: "75", created_at: "2018-01-..., 
          {id: 179, uid: "1", when: "2018-01-17", gingerbread: "32", created_at... }];
$scope.totals = {};
for (var i = 0; i < myArray.length; i++) {
   $scope.totals[myarray[i].when] +=  +myarray[i].gingerbread; //use '+' to coerce a number
}

然后遍历 HTML 中的 $scope.totals 对象(您可能还需要将对象键/值对放入一个对象数组中)