javascript - For inside other for in javascript 无法正常工作

Question

我有这个代码

for (var i = 0; i < vm.items.users.data.length; i++) {
      var user = vm.items.users.data[i];
      user.goals_by_brands = [];
      var brands = [];
      vm.items.brands.data.forEach( function(element, index) {
        brands.push(element);
      });
      console.log("brands", brands)
      console.log("vm.items.brands.data", vm.items.brands.data)
      brands.forEach( function(brand) {
        brand.goals_by_months = [];
        brand.user = user;
        constants.MONTHS.forEach( function(month) {
          brand.goals_by_months.push({goals: [], total_month_goal: 0, total_month_accumulated: 0});
        });
        user.goals_by_brands.push(brand);
      });

}

我写了这行:

var brands = [];
      vm.items.brands.data.forEach( function(element, index) {
        brands.push(element);
      });

但我也尝试过克隆数组(slice() 函数)，它的作用是相同的。

在brands数组和vm.items.brands.data数组中，出现了相同的情况； vm.items.users.data 数组中的最后一个用户。

不知道为什么..

我想这样做:

• 我有用户数组。 -> vm.items.users.data
• 我有很多品牌。 -> vm.items.brands.data
• 我有几个月的数组。 -> 常量.MONTHS

我想向每个品牌添加包含此对象的数组 -> {goals: [],total_month_goal: 0,total_month_accumulated: 0} 12 次(每月一次)。 然后这个品牌，我想添加到每个用户 ->

[
      {
        id: "user1",
        name: "user1",
        goals_by_brands: [
          {
            id: "brand1",
            name: "brand1",
            goals_by_months: [
              {goals: [], total_month_goal: 0, total_month_accumulated: 0},
              {goals: [], total_month_goal: 0, total_month_accumulated: 0},
              {goals: [], total_month_goal: 0, total_month_accumulated: 0},
              {goals: [], total_month_goal: 0, total_month_accumulated: 0},
              {goals: [], total_month_goal: 0, total_month_accumulated: 0},
              {goals: [], total_month_goal: 0, total_month_accumulated: 0},
              {goals: [], total_month_goal: 0, total_month_accumulated: 0},
              {goals: [], total_month_goal: 0, total_month_accumulated: 0},
              {goals: [], total_month_goal: 0, total_month_accumulated: 0},
              {goals: [], total_month_goal: 0, total_month_accumulated: 0},
              {goals: [], total_month_goal: 0, total_month_accumulated: 0},
              {goals: [], total_month_goal: 0, total_month_accumulated: 0}
            ]
          }
        ]

    }]

所以我想将用户添加到 goal_by_brands 的每个品牌对象中。

对不起我的英语。

Answer 1

因此，您的代码的问题在于您拥有“品牌”引用，而不是品牌的副本。由于您正在更改主要引用，因此品牌会不断被覆盖，因此请在循环中进行此更改。

var brands = []; 
vm.items.brands.data.forEach( function(element, index) { 
brands.push(element); //This pushes the reference which remains the same.
});

将此推送线更改为

var newBrand = JSON.parse(JSON.stringify(element))) //Make a deep copy of the element
brands.push(newBrand)