根据特定值搜索并返回键值对答案

【问题标题】：search and return key value pair based on a specific value根据特定值搜索并返回键值对
【发布时间】：2018-08-25 06:00:29
【问题描述】：

我是 Angular 的新手，第一次做键值对。我正在尝试根据嵌套键值映射中的特定值获取键值对。我有一个嵌套的 JSON 数据格式：

journey = {
"20180201": [{
        "journeyId": 1001,
        "Number": "001",
        "DriverName":"Alex",
        "Transporter": {
            "id": "T1",
            "number": "AN01001",
            "Company": "Tranzient"
        }
        "place": [{"id":001,"value":"Washington DC" }]
                  [{"id":002,"value":"Canberra"}]
    }]
    [{
       "journeyId": 1002,
        "Number": "001",
        "DriverName":"Tom",
        "Transporter": {
            "id": "T2",
            "number": "AN01002",
            "Company": "Trax"
        }
        "place": [{"id":002,"value":"Canberra" }]
                  [{"id":004,"value":"Vienna"}]
    }]
    [{
         "journeyId": 1003,
        "Number": "004",
        "DriverName":"Jack",
        "Transporter": {
            "id": "T3",
            "number": "AN01003",
            "Company": "Trax"
        }
        "place": [{"id":001,"value":"Washington DC" }]
                  [{"id":004,"value":"Vienna"}]
    }],
"20180211": [{
         "journeyId": 1004,
        "Number": "005",
        "DriverName":"Jack",
        "Transporter": {
            "id": "T3",
            "number": "AN01013",
            "Company": "Trax"
        }
        "place": [{"id":005,"value":"Bridgetown" }]
                  [{"id":006,"value":"Ottawa"}]
                  [{"id":004,"value":"Vienna"}]

    }]
    [{
       "journeyId": 1005,
        "Number": "005",
        "DriverName":"Jerry",
        "Transporter": {
            "id": "T3",
            "number": "AN01020",
            "Company": "Trax"
        }
        "place": [{"id":005,"value":"Bridgetown" }]
                  [{"id":006,"value":"Ottawa"}]
    }],
"20180301": [{
        "journeyId": 1006,
        "Number": "005",
        "DriverName":"demy",
        "Transporter": {
            "id": "T3",
            "number": "AN01003",
            "Company": "Trax"
        }
        "place": [{"id":005,"value":"Bridgetown" }]
                  [{"id":006,"value":"Ottawa"}]
    }]

};

我正在尝试过滤掉所有具有 place[value]=Vienna 的旅程键值对。

我的预期输出应该是：

journey = {
    "20180201": 
        [{
           "journeyId": 1002,
            "Number": "001",
            "DriverName":"Tom",
            "Transporter": {
                "id": "T2",
                "number": "AN01002",
                "Company": "Trax"
            }
            "place": [{"id":002,"value":"Canberra" }]
                      [{"id":004,"value":"Vienna"}]
        }]
        [{
             "journeyId": 1003,
            "Number": "004",
            "DriverName":"Jack",
            "Transporter": {
                "id": "T3",
                "number": "AN01003",
                "Company": "Trax"
            }
            "place": [{"id":001,"value":"Washington DC" }]
                      [{"id":004,"value":"Vienna"}]
        }],
    "20180211": [{
             "journeyId": 1004,
            "Number": "005",
            "DriverName":"Jack",
            "Transporter": {
                "id": "T3",
                "number": "AN01013",
                "Company": "Trax"
            }
            "place": [{"id":005,"value":"Bridgetown" }]
                      [{"id":006,"value":"Ottawa"}]
                      [{"id":004,"value":"Vienna"}]

        }]

};

我不知道从哪里开始。

【问题讨论】：

为什么你不只是循环那个 JSON？并且内部循环（forEach 例如）按条件 if (jorney.place.value === Vienna) 收集您希望的所有数据
@Sh.Pavel 在循环内我也需要返回日期（“20180211”），这没有发生，而是给我所有的日期（因为在循环内）

标签： javascript angular dictionary hashmap key-value

【解决方案1】：

您必须使用 javascript 中的 filter() 方法过滤您的数组。 https://www.w3schools.com/Jsref/jsref_filter.asp.

例子：

// your array containing objects
var arr = [{
    id: 2,
    text: 'asdasdasd'
  },
  {
    id: 3,
    text: 'mytext'
  },
  {
    id: 1,
    text: 'mytext'
  }];
// filter array by property 'text' = 'mytext'
var filteredArray = arr.filter(function(item) {
  return item.text === 'mytext';
});

因此，您现在将拥有filteredArray：

[{
  id: 3,
  text: 'mytext'
},
{
  id: 1,
  text: 'mytext'
}]

【讨论】：

但是我里面也有很多嵌套的对和数组。我如何循环遍历所有数组->键值对->数组->键值对
例如，您可以过滤第一个包含旅程的数组，然后在过滤器方法中调用“find()”方法以仅过滤包含特定值的对象：var filtered = arr.filter(function(journey) { return journey.place.find(function(place) { return place.value === 'Vienna'; }); });