编辑对象数组中的对象属性

Question

我有一个 class itemCollection 存储有关购买的信息。此 class 的数组 _items 为属性，其中购买是商店。当用户在购物车中添加新购买时，此 class 使用 addItem 方法将该项目添加到 _items 属性如果它已经有此项目，则此方法迭代 quantity 属性如果不在数组中添加新项目。

Problem is that instead of adding new item in array when other item is chosen its keeps incrementing quantity 属性 of a first item that was added.

cartCollection class（对象）：

var cartCollection = {
    _items: [],
    addItem: function(obj) {
      'use strict';
      var purchase = {
        item: {
          id: obj.id,
          name: obj.name,
          price: obj.price
        },
        thisItemTotal: obj.price,
        quantity: 1
      };
      var result = _.findWhere(this._items, purchase.item.id);
      console.log(result);
      if (typeof result != 'undefined') {
        //console.log(result);
        var index = _.findIndex(this._items, {
          id: result.item.id
        });
        //console.log(index);
        result.quantity++;
        this._items[index] = result;
        this._itemTotalPrice();
      } else if (typeof result === 'undefined') {
        console.log("Im was called!");
        this._items.push(purchase);
        console.log(this._items);
      }
    },
    ...

Answer 1

您的 findWhere 语句已损坏。应该是：

var result = _.findWhere(this._items, {id:purchase.item.id});

祝你好运

Answer 2

由于 purchase 没有 ID，但是 "item" 有 ID，正确的查找语句应该是：

var result = _.find(this._items, function(item) {
   return item.item.id == purchase.item.id;
});

最好将 _items 重命名为 _purchases 以消除歧义

完整的代码应该是这样的：

addItem: function(obj) {
  'use strict';
  var purchase = {
    item: _.pick(obj, 'id', 'name', 'price')
    thisItemTotal: obj.price,
    quantity: 1
  };

  var result = _.find(this._items, function(item) {
    return item.item.id == purchase.item.id;
  });

  console.log(result);

  if (result) {
    result.quantity++;
    this._itemTotalPrice();
  }
  else {
    console.log("Im was called!");
    this._items.push(purchase);
    console.log(this._items);
  }
},

编辑对象数组中的对象属性

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编辑对象数组中的对象 属性

Edit property of an object in array of objects

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编辑对象数组中的对象属性