Question

我有两个对象数组，我想根据条件得到key的值。

我想根据deltaArr中的键id从旧数组中获取googleId个值。

因此，当 googleId of deltaArr 与 googleId of oldArr 匹配时，我希望在该索引处获得oldArr的id并存储在数组中。

function getPrimaryKeys(deltaArr, oldArr){
    console.log('deltaArr........ ', JSON.stringify(deltaArr, null, 2));
    console.log('oldArr........ ', JSON.stringify(oldArr, null, 2));
    var primaryKeys = [];
    for(var i = 0; i< deltaArr.length; i++){
        if(deltaArr[i].hasOwnProperty('googleId') && deltaArr[i].googleId == oldArr[i].googleId){
            primaryKeys.push(oldArr[i].id);
        }
    }
    return primaryKeys;
}

deltaArr：

[
    {
        "contact": {
          "address": {
            "home": "",
            "office": ""
          },
          "email": {
            "home": "",
            "other": "",
            "work": ""
          },
          "im": {
            "aim": "",
            "icq": "",
            "skype": ""
          },
          "phone": {
            "cell": "+91-1234-567-891",
            "home": "",
            "work": "",
            "e164": "+911234567891"
          }
        },
        "googleId": "2bf235bd8a846814",
        "createdDate": "2016-12-31T13:03:09.203Z",
        "name": "Test1",
        "profileData": ""
    }
]

oldArr：

[
  {
    "contact": {
      "address": {
        "home": "",
        "office": ""
      },
      "email": {
        "home": "",
        "other": "",
        "work": ""
      },
      "im": {
        "aim": "",
        "icq": "",
        "skype": ""
      },
      "phone": {
        "cell": "+91-1234-567-896",
        "e164": "+911234567896",
        "home": "",
        "work": ""
      }
    },
    "createdDate": "2016-12-31T12:59:08.959Z",
    "googleId": "3e98af288ff825f7",
    "id": "2e4009de-4bce-4f02-b33c-415ad688f1c2",
    "name": "Test6",
    "profileData": ""
  },
  {
    "contact": {
      "address": {
        "home": "",
        "office": ""
      },
      "email": {
        "home": "",
        "other": "",
        "work": ""
      },
      "im": {
        "aim": "",
        "icq": "",
        "skype": ""
      },
      "phone": {
        "cell": "+91-1234-567-890",
        "e164": "+911234567890",
        "home": "",
        "work": ""
      }
    },
    "createdDate": "2016-12-31T12:59:08.952Z",
    "googleId": "2bf235bd8a846814",
    "id": "411b2507-64a1-46d6-812b-8216446676e3",
    "name": "Test0",
    "profileData": ""
  },
  {
    "contact": {
      "address": {
        "home": "",
        "office": ""
      },
      "email": {
        "home": "",
        "other": "",
        "work": ""
      },
      "im": {
        "aim": "",
        "icq": "",
        "skype": ""
      },
      "phone": {
        "cell": "+91-1234-567-895",
        "e164": "+911234567895",
        "home": "",
        "work": ""
      }
    },
    "createdDate": "2016-12-31T12:59:08.951Z",
    "googleId": "20735d9e8df44423",
    "id": "46f579cb-dbda-49f1-8eb6-df621692e023",
    "name": "Test5",
    "profileData": ""
  }
]

如果您看到两个阵列中都存在"googleId": "2bf235bd8a846814"。我尝试了上述内容，但是给出了undefined

注意：两个数组的长度因动态数据而异。在这种情况下，我不知道id或googleId

的价值是什么

Answer 1

您可以为googleId使用哈希表，如果找到已知的old，则检查googleId数组，然后将id添加到结果数组中。

哈希表是一个对象，googleId为关键字，true为值。

{
    "2bf235bd8a846814": true
}

这对于检查old数组是必要的。如果散列为'2bf235bd8a846814'，则散列表返回true，否则返回undefied，这是if条件的假值。

＆＃13;

function getId(delta, old) {
    var googleId = Object.create(null),
        result = [];

    delta.forEach(function (a) {
        googleId[a.googleId] = true;
    });
    console.log(googleId);
    old.forEach(function(a) {
        if (googleId[a.googleId]) {
            result.push(a.id);
        }
    });
    return result;
}

var deltaArray = [{ "contact": { "address": { "home": "", "office": "" }, "email": { "home": "", "other": "", "work": "" }, "im": { "aim": "", "icq": "", "skype": "" }, "phone": { "cell": "+91-1234-567-891", "home": "", "work": "", "e164": "+911234567891" } }, "googleId": "2bf235bd8a846814", "createdDate": "2016-12-31T13:03:09.203Z", "name": "Test1", "profileData": "" }],
    oldArray = [{ "contact": { "address": { "home": "", "office": "" }, "email": { "home": "", "other": "", "work": "" }, "im": { "aim": "", "icq": "", "skype": "" }, "phone": { "cell": "+91-1234-567-896", "e164": "+911234567896", "home": "", "work": "" } }, "createdDate": "2016-12-31T12:59:08.959Z", "googleId": "3e98af288ff825f7", "id": "2e4009de-4bce-4f02-b33c-415ad688f1c2", "name": "Test6", "profileData": "" }, { "contact": { "address": { "home": "", "office": "" }, "email": { "home": "", "other": "", "work": "" }, "im": { "aim": "", "icq": "", "skype": "" }, "phone": { "cell": "+91-1234-567-890", "e164": "+911234567890", "home": "", "work": "" } }, "createdDate": "2016-12-31T12:59:08.952Z", "googleId": "2bf235bd8a846814", "id": "411b2507-64a1-46d6-812b-8216446676e3", "name": "Test0", "profileData": "" }, { "contact": { "address": { "home": "", "office": "" }, "email": { "home": "", "other": "", "work": "" }, "im": { "aim": "", "icq": "", "skype": "" }, "phone": { "cell": "+91-1234-567-895", "e164": "+911234567895", "home": "", "work": "" } }, "createdDate": "2016-12-31T12:59:08.951Z", "googleId": "20735d9e8df44423", "id": "46f579cb-dbda-49f1-8eb6-df621692e023", "name": "Test5", "profileData": "" }];

console.log(getId(deltaArray, oldArray));

＆＃13;

.as-console-wrapper { max-height: 100% !important; top: 0; }

＆＃13;

Answer 2

您可以通过 google_id 值（使用Map）对旧数组进行哈希处理，并将其作为delta数组上.map()调用的上下文提供：

＆＃13;

function collect(delta, old) {
    return delta.map(function (d) {
        return this.get(d.googleId).id
    }, new Map(old.map ( o => [o.googleId, o] )));
}

var deltaArr = [{ "contact": { "address": { "home": "", "office": "" }, "email": { "home": "", "other": "", "work": "" }, "im": { "aim": "", "icq": "", "skype": "" }, "phone": { "cell": "+91-1234-567-891", "home": "", "work": "", "e164": "+911234567891" } }, "googleId": "2bf235bd8a846814", "createdDate": "2016-12-31T13:03:09.203Z", "name": "Test1", "profileData": "" }];
var oldArr = [{ "contact": { "address": { "home": "", "office": "" }, "email": { "home": "", "other": "", "work": "" }, "im": { "aim": "", "icq": "", "skype": "" }, "phone": { "cell": "+91-1234-567-896", "e164": "+911234567896", "home": "", "work": "" } }, "createdDate": "2016-12-31T12:59:08.959Z", "googleId": "3e98af288ff825f7", "id": "2e4009de-4bce-4f02-b33c-415ad688f1c2", "name": "Test6", "profileData": "" }, { "contact": { "address": { "home": "", "office": "" }, "email": { "home": "", "other": "", "work": "" }, "im": { "aim": "", "icq": "", "skype": "" }, "phone": { "cell": "+91-1234-567-890", "e164": "+911234567890", "home": "", "work": "" } }, "createdDate": "2016-12-31T12:59:08.952Z", "googleId": "2bf235bd8a846814", "id": "411b2507-64a1-46d6-812b-8216446676e3", "name": "Test0", "profileData": "" }, { "contact": { "address": { "home": "", "office": "" }, "email": { "home": "", "other": "", "work": "" }, "im": { "aim": "", "icq": "", "skype": "" }, "phone": { "cell": "+91-1234-567-895", "e164": "+911234567895", "home": "", "work": "" } }, "createdDate": "2016-12-31T12:59:08.951Z", "googleId": "20735d9e8df44423", "id": "46f579cb-dbda-49f1-8eb6-df621692e023", "name": "Test5", "profileData": "" }];

console.log(collect(deltaArr, oldArr));

＆＃13;

根据另一个对象的密钥获取密钥的值

2 个答案: