javascript - 比较两个对象数组并将具有匹配值的对象添加到第一个对象数组

Question

我有 2 个类似这样的对象数组

var pollAnswers = [
        {
            "_id": "5b58afa0c767e12c9869e540",
            "pollId": "5b58afa0c767e12c9869e53f",
            "option": "Google",
        },
        {
            "_id": "5b58afa0c767e12c9869e541",
            "pollId": "5b58afa0c767e12c9869e53f",
            "option": "The Jetsons",
        },
        {
            "_id": "5b58afa0c767e12c9869e542",
            "pollId": "5b58afa0c767e12c9869e53f",
            "option": "Family  Guy",
        },
        {
            "_id": "5b593b195c420e28089daf9d",
            "pollId": "5b593b195c420e28089daf9c",
            "option": "Yes. Through loyalty programmes.",
        },
        {
            "_id": "5b593b195c420e28089daf9e",
            "pollId": "5b593b195c420e28089daf9c",
            "option": "What Hunger Crisis?",
        },
        {
            "_id": "5b5953d775c4401e7052127c",
            "pollId": "5b5953d775c4401e7052127b",
            "option": "Yes, absolutely",
        },
        {
            "_id": "5b5953d775c4401e7052127d",
            "pollId": "5b5953d775c4401e7052127b",
            "option": "No, absolutely not",
        }
    ]

var polls = [
        {
            "_id": "5b58afa0c767e12c9869e53f",
            "pollName": "Consumers in 2070 (How about now?)",
            "pollQuestion": "Which animated series will consumers in 2070 resemble the most?",
        },
        {
            "_id": "5b593b195c420e28089daf9c",
            "pollName": "World Hunger",
            "pollQuestion": "Can Internet-based services solve the Hunger Crisis?",
        },
        {
            "_id": "5b5953d775c4401e7052127b",
            "pollName": "Make things Work Again",
            "pollQuestion": "Make things Work",
        }
    ]

我需要将 pollAnsers 中的 pollId 与 polls 中的 _id 进行比较，以通过以下方式将匹配的答案添加到相应的 pollQuestions

"polls": [
        {
            "_id": "5b58afa0c767e12c9869e53f",
            "pollName": "Consumers in 2070 (How about now?)",
            "pollQuestion": "Which animated series will consumers in 2070 resemble the most?",
            "answersList": [
              {
                "_id": "5b58afa0c767e12c9869e540",
                "pollId": "5b58afa0c767e12c9869e53f",
                "option": "Google",
              },
              {
                "_id": "5b58afa0c767e12c9869e541",
                "pollId": "5b58afa0c767e12c9869e53f",
                "option": "The Jetsons",
              },
              {
                "_id": "5b58afa0c767e12c9869e542",
                "pollId": "5b58afa0c767e12c9869e53f",
                "option": "Family  Guy",
              },             
            ]
        },
        {
            "_id": "5b593b195c420e28089daf9c",
            "pollName": "World Hunger",
            "pollQuestion": "Can Internet-based services solve the Hunger Crisis?",
            "answersList": [
                {
                  "_id": "5b593b195c420e28089daf9d",
                  "pollId": "5b593b195c420e28089daf9c",
                  "option": "Yes. Through loyalty programmes.",
                },
                {
                  "_id": "5b593b195c420e28089daf9e",
                  "pollId": "5b593b195c420e28089daf9c",
                  "option": "What Hunger Crisis?",
                }
            ]
        },
        {
            "_id": "5b5953d775c4401e7052127b",
            "pollName": "Make things Work Again",
            "pollQuestion": "Make things Work",
            "answersList": [
              {
                "_id": "5b5953d775c4401e7052127c",
                "pollId": "5b5953d775c4401e7052127b",
                "option": "Yes, absolutely",
              },
              {
                "_id": "5b5953d775c4401e7052127d",
                "pollId": "5b5953d775c4401e7052127b",
                "option": "No, absolutely not",
              }
            ]
        }
    ]

我一直在尝试所有可能性，例如使用 map 、过滤器、for 循环等，但无法获得结果，我对此还很陌生，请帮忙!谢谢

Answer 1

您可以通过简单易懂的代码使用两个 forEach() 循环:

var pollAnswers = [
        {
            "_id": "5b58afa0c767e12c9869e540",
            "pollId": "5b58afa0c767e12c9869e53f",
            "option": "Google",
        },
        {
            "_id": "5b58afa0c767e12c9869e541",
            "pollId": "5b58afa0c767e12c9869e53f",
            "option": "The Jetsons",
        },
        {
            "_id": "5b58afa0c767e12c9869e542",
            "pollId": "5b58afa0c767e12c9869e53f",
            "option": "Family  Guy",
        },
        {
            "_id": "5b593b195c420e28089daf9d",
            "pollId": "5b593b195c420e28089daf9c",
            "option": "Yes. Through loyalty programmes.",
        },
        {
            "_id": "5b593b195c420e28089daf9e",
            "pollId": "5b593b195c420e28089daf9c",
            "option": "What Hunger Crisis?",
        },
        {
            "_id": "5b5953d775c4401e7052127c",
            "pollId": "5b5953d775c4401e7052127b",
            "option": "Yes, absolutely",
        },
        {
            "_id": "5b5953d775c4401e7052127d",
            "pollId": "5b5953d775c4401e7052127b",
            "option": "No, absolutely not",
        }
    ]

var polls = [
        {
            "_id": "5b58afa0c767e12c9869e53f",
            "pollName": "Consumers in 2070 (How about now?)",
            "pollQuestion": "Which animated series will consumers in 2070 resemble the most?",
        },
        {
            "_id": "5b593b195c420e28089daf9c",
            "pollName": "World Hunger",
            "pollQuestion": "Can Internet-based services solve the Hunger Crisis?",
        },
        {
            "_id": "5b5953d775c4401e7052127b",
            "pollName": "Make things Work Again",
            "pollQuestion": "Make things Work",
        }
];

polls.forEach((poll) => {
  poll.answerList = [];
  pollAnswers.forEach((pollAnswer) => {
    if(pollAnswer.pollId === poll._id){
      poll.answerList.push(pollAnswer);
    }
  });
});
console.log(polls);