在 Typescript 中过滤嵌套数组对象的数组

Question

我在过滤嵌套数组数据集时遇到了一些麻烦。例如，我有下面的数据数组列表：

let list = [
{
  "percentage": 50.0,
  "budget": "online",
  "ruleName": "C1"
},
{
  "percentage": 50.0,
  "budget": "offline",
  "ruleName": "C1"
},
{
  "percentage": 50.0,
  "budget": "other",
  "ruleName": "C4"
}

]

现在我想使用 .map 或 .filter 实现以下结果，并考虑 父数组 的预算属性和 子组数组 匹配，那么它应该只返回 group 内匹配的 object 而不是全部：

[
  {
    "budget": "online",
    "ruleName": "C1",
    "group": [
        {
            "budget": "onlne",
            "percentage": 50.0
        }
    ]
  },

  {
    "budget": "offline",
    "ruleName": "C1",
    "group": [
        {
            "budget": "offline",
            "percentage": 50.0
        }
    ]
  },

  {
    "budget": "other",
    "ruleName": "C4",
    "group": [
        {
            "budget": "other",
            "percentage": 0
        }
    ]
  }

]

所以我执行了以下操作，但结果与上面的预期结果不匹配：

this.group = list.map((i)=>{
  return {
    budget: i.budget,
  }
})
this.payments = list.map((i)=>{
  return {
    budget: i.budget,
    amtPercentage: i.percentage ? i.percentage : 0,
    rulename: i.rulename,
    group: this.group
  }
})

以上代码执行后的结果如下：

[
{
    "budget": "online",
    "ruleName": "C1",
    "group": [
        {
            "budget": "onlne",
            "percentage": 50.0
        },
        {
            "budget": "offline",
            "percentage": 50.0
        },
        {
            "budget": "other",
            "percentage": 0
        }
    ]
},

{
    "budget": "offline",
    "ruleName": "C1",
    "group": [
        {
            "budget": "onlne",
            "percentage": 50.0
        },
        {
            "budget": "offline",
            "percentage": 50.0
        },
        {
            "budget": "other",
            "percentage": 0
        }
    ]
},

{
    "budget": "other",
    "ruleName": "C4",
    "group": [
        {
            "budget": "onlne",
            "percentage": 50.0
        },
        {
            "budget": "offline",
            "percentage": 50.0
        },
        {
            "budget": "other",
            "percentage": 0
        }
    ]
}

]

我不知道如何根据条件过滤嵌套组数组，如果父数组预算属性等于 group.budget 属性，那么它应该只返回该对象而不是全部。

我将非常感谢您的帮助。提前谢谢了。

注意：我正在使用带有 angular-2 的打字稿。

Answer 1

this.payments = list.map((i)=>{
  return {
    budget: i.budget,
    amtPercentage: i.percentage ? i.percentage : 0,
    rulename: i.rulename,
    group: this.group.filter((x) => i.budget === x.budget)
  }
})

编辑简化：

this.payments = list.map((listElement) => ({
    ...listElement,
    amtPercentage: listElement.percentage || 0,
    group: this.group.filter((groupElement) => listElement.budget === groupElement.budget)
}))