JS - 嵌套 for 循环 - 按键比较 2 个数组，返回 4 个新数组，每个数组匹配和不匹配

Question

为这个问题做了一个演示 -

数组 -

const arr1 = [
  {
    key: "daniel|21",
    name: "daniel",
    age: 21,
    city: "NYC"
  },
  {
    key: "kosta|28",
    name: "kosta",
    age: 28,
    city: "NYC"
  }
];

const arr2 = [
  {
    key: "daniel|21",
    name: "daniel",
    age: 21,
    city: "TLV"
  },
  {
    key: "simon|24",
    name: "simon",
    age: 24,
    city: "NYC"
  },
  {
    key: "david|22",
    name: "david",
    age: 22,
    city: "NYC"
  }
];

用于赋值的空数组 -

let arr1Match = [];
let arr1Unmatch = [];

let arr2Match = [];
let arr2Unmatch = [];

For循环-

for (let i = 0; i < arr1.length; i++) {
for (let j = 0; j < arr2.length; j++) {
    const arr1Key = arr1[i].key;
    const arr2Key = arr2[j].key;

    if (arr1Key === arr2Key) {
        arr1Match.push(arr1[i])
        arr2Match.push(arr2[i])
    } else {
        arr1Unmatch.push(arr1[i])
        arr2Unmatch.push(arr2[i])
    }
}

}

我在输出什么 -

console.log(arr1Match);
console.log(arr1Unmatch);

console.log(arr2Match);
console.log(arr2Unmatch);

输出 -

arr1Match：[{ "key": "daniel|21", "name": "daniel", "age": 21, "city": "NYC" }]

arr1Unmatch：[{ "key": "daniel|21", "name": "daniel", "age": 21, "city": "NYC" }, { "key": "daniel|21", "name": "daniel", "age": 21, "city": "NYC" }, { "key": "kosta|28", "name": "kosta", "age": 28, "city": "NYC" }, { "key": "kosta|28", "name": "kosta", "age": 28, "city": "NYC" }, { "key": "kosta|28", "name": "kosta", "age": 28, "city": "NYC" }]

arr2Match： [{ "key": "daniel|21", "name": "daniel", "age": 21, "city": "TLV" }]

arr2Unmatch：[{ "key": "daniel|21", "name": "daniel", "age": 21, "city": "TLV" }, { "key": "daniel|21", "name": "daniel", "age": 21, "city": "TLV" }, { "key": "simon|24", "name": "simon", "age": 24, "city": "NYC" }, { "key": "simon|24", "name": "simon", "age": 24, "city": "NYC" }, { "key": "simon|24", "name": "simon", "age": 24, "city": "NYC" }]

想要的输出 -

arr1Match：[{ "key": "daniel|21", "name": "daniel", "age": 21, "city": "NYC" }]

arr1Unmatch：[{ "key": "kosta|28", "name": "kosta", "age": 28, "city": "NYC" }]

arr2Match：[{ "key": "daniel|21", "name": "daniel", "age": 21, "city": "TLV" }]

arr2Unmatch：[{ "key": "simon|24", "name": "simon", "age": 24, "city": "NYC" }, { "key": "david|22", "name": "david", "age": 22, "city": "NYC" }]

我需要循环遍历数组中的所有值并返回每个值的所有匹配项和不匹配项。 如果有匹配项，我需要将属性从 arr2 分配到 arr1

Answer 1

我不太确定我理解你的问题，这是你想要的结果吗？

const arr1 = [{
    key: "daniel|21",
    name: "daniel",
    age: 21,
    city: "NYC"
  },
  {
    key: "kosta|28",
    name: "kosta",
    age: 28,
    city: "NYC"
  }
];

const arr2 = [{
    key: "daniel|21",
    name: "daniel",
    age: 21,
    city: "TLV"
  },
  {
    key: "simon|24",
    name: "simon",
    age: 24,
    city: "NYC"
  },
  {
    key: "david|22",
    name: "david",
    age: 22,
    city: "NYC"
  }
];

const arr1Keys = arr1.map(a => a.key);
const arr2Keys = arr2.map(a => a.key);
const keys = [...arr1Keys, ...arr2Keys];
const repeat = keys.filter((o, i) => keys.indexOf(o) !== i);
const unique = [...new Set(keys)].filter(o => !repeat.includes(o));

const arr1Match = arr1.filter(a => repeat.includes(a.key));
const arr1Unmatch = arr1.filter(a => unique.includes(a.key));
const arr2Match = arr2.filter(a => repeat.includes(a.key));
const arr2Unmatch = arr2.filter(a => unique.includes(a.key));
const arr1Match2 = arr1Match.map(a1 => {
  let obj = arr2Match.find(a2 => a2.key == a1.key);
  return {...obj, city: obj.city}
});
const arr1Match3 = arr1Match.map(a1 => arr2Match.find(a2 => a2.key == a1.key));

console.log('arr1Match before', JSON.stringify(arr1Match));
console.log('arr1Match overwrite city', JSON.stringify(arr1Match2));
console.log('arr1Match overwrite all', JSON.stringify(arr1Match3));
console.log('arr1Unmatch', JSON.stringify(arr1Unmatch));
console.log('arr2Match', JSON.stringify(arr2Match));
console.log('arr2Unmatch', JSON.stringify(arr2Unmatch));

Answer 2

找到常见对象并更新它们的方法。

const
    update = (a, b) => {
        const
            fn = o => o.key,
            references = Object.fromEntries(a.map(o => [fn(o), o]));

        b.forEach(o => {
            const target = references[fn(o)];
            if (target) Object.assign(target, o);
        });
    }
    array1 = [{ key: "daniel|21", name: "daniel", age: 21, city: "NYC" }, { key: "kosta|28", name: "kosta", age: 28, city: "NYC" }],
    array2 = [{ key: "daniel|21", name: "daniel", age: 21, city: "TLV" }, { key: "simon|24", name: "simon", age: 24, city: "NYC" }, { key: "david|22", name: "david", age: 22, city: "NYC" }];

update(array1, array2);

console.log(array1); // inclusive the one with updates!

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您可以获取公共键并获取每个数组的分区。

const
    match = (a, b, fn) => {
        const 
            getCommon = (a, b) => {
                const c = {};
                a.forEach(o => c[fn(o)] = false);
                b.forEach(o => c[fn(o)] = fn(o) in c);
                return c;
            };
            common = getCommon(a, b, fn),
            getParts = (a, c) => a.reduce((r, o) => (r[+!common[fn(o)]].push(o), r), [[], []]);
            
        return [
            getParts(a, common),
            getParts(b, common)
        ];
    }
    array1 = [{ key: "daniel|21", name: "daniel", age: 21, city: "NYC" }, { key: "kosta|28", name: "kosta", age: 28, city: "NYC" }],
    array2 = [{ key: "daniel|21", name: "daniel", age: 21, city: "TLV" }, { key: "simon|24", name: "simon", age: 24, city: "NYC" }, { key: "david|22", name: "david", age: 22, city: "NYC" }],
    [
        [arr1Match, arr1Unmatch],
        [arr2Match, arr2Unmatch]
    ] = match(array1, array2, o => o.key);

console.log(arr1Match);
console.log(arr1Unmatch);

console.log(arr2Match);
console.log(arr2Unmatch);

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