我有2个看起来像这样的对象数组
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与民意测验中的_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中
"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的方法，例如使用map，filter，for循环等，但未能获得结果，对此我还是很陌生，请帮助！谢谢
答案 0 :(得分：1)
您可以使用Array#forEach遍历民意调查，在每次迭代中，使用Array#filter查找相关答案，并将其分配给民意调查对象：
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.answersList = pollAnswers.filter(ans => ans.pollId === poll._id);
})
console.log(polls);
答案 1 :(得分：1)
您可以使用两个forEach()循环使用简单易懂的代码：
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);
答案 2 :(得分：1)
您可以利用Map的功效并首先迭代目标数组以填充地图并为结果集生成独立的对象。
然后迭代所有答案并将其分配给相关的民意测验。
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" }],
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" }],
map = new Map,
result = {
polls: polls.map(p => {
var answersList = [];
map.set(p._id, answersList);
return Object.assign({}, p, { answersList });
})
};
pollAnswers.forEach(p => map.get(p.pollId).push(p));
console.log(result);.as-console-wrapper { max-height: 100% !important; top: 0; }
答案 3 :(得分：1)
我的reduce方法：
var pollsWithAnswers = pollAnswers.reduce(function(polls, answer) {
var index = polls.findIndex(function(pol) {
return pol._id == answer.pollId;
})
if (index > -1) {
if (polls[index].anwerList instanceof Array) polls[index].anwerList.push(answer);
else polls[index].anwerList = [answer]
}
return polls
}, polls.slice())
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",
}
]
console.log(pollAnswers.reduce(function(polls, answer) {
var index = polls.findIndex(function(pol) {
return pol._id == answer.pollId;
})
if (index > -1) {
if (polls[index].anwerList instanceof Array) polls[index].anwerList.push(answer);
else polls[index].anwerList = [answer]
}
return polls
}, polls.slice()))
答案 4 :(得分：0)
这是另一种使用map和filter且简单且不可变的方式的解决方案，这样您的原始数组就不会发生突变。
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"}];
const pollsWithAnswers = polls.map(poll => ({
...poll,
answersList: pollAnswers.filter(answer => poll._id === answer.pollId)
}));
console.log(pollsWithAnswers);
希望有帮助