回傳具有相似結構但已過濾的物件

我有以下物件：

const myObject = {
"-Lz8YxHiwp8QZW3TqAFn": Object {
  "first": "Breanna",
  "last": "Blah",
},
"-Lz8YxHqQXWoaGOFRLrO": Object {
  "first": "Joshua",
  "last": "Blah",
},
"-Lz8YxHsMItaaTVNyQRE": Object {
  "first": "Joziah",
  "last": "Blah",
},
"-Lz8YxHwuVBMWl0Go6C5": Object {
  "first": "Lino",
  "last": "Blah",
},
"-Lz8YxHy0S-QkDaE1PkX": Object {
  "first": "Rebecca",
  "last": "Blah",
},
"-Lz8YxI5IItUiXX6rFn_": Object {
  "first": "Rosario",
  "last": "Blah",
},
"-Lz8YxIB_YTBF8liL855": Object {
  "first": "Alissa",
  "last": "Blah",
}
}

然后我有一個包含以下內容的集合：

const mySet = {
  "-Lz8YxMp-V0TfiwrkM49",
  "-Lz8YxNQP2WkkO0qpkRJ",
  "-Lz8YxHy0S-QkDaE1PkX",
  "-MmFNgjyopU3E8z5g-zU",
  "-Lz8YxLVi_uZp_RkcRIH",
  "-MuEgimJOIbPw3GyKBJ3",
  "-Lz8YxOFpVHx2xPI1mUu",
  "-Lz8YxJ-_wuk8bmEyvGT",
  "-Lz8YxKj5WXY1oNwylQ4",
  "-Lz8YxN87U1YM6_fKgq1",
  "-Lz8YxOI4qszJvZhrSde",
  "-Lz8YxI5IItUiXX6rFn_",
}

我只需要回傳與 mySet 中的專案匹配的物件的 myObject。我已經用地圖完成了這個，但它把 myObject 變成了一個陣列。下面使用 map 并回傳一個我不能用于這種特殊情況的陣列。

// const addGroupMembers = Object.entries(members)
//   .filter(([key]) => {
//     eachHit  ;
//     console.log(key)
//     return attendanceGroupMembers.has(key);
//   })
//   .map(([_, members]) => {
//     eachHit  ;
//     console.log('in map')
//     return members;
//   });

我想保留 myObject 結構，但只找到找到的專案。知道我怎么能做到這一點嗎？

uj5u.com熱心網友回復：

當然，只需使用 .reduce 分配給一個新物件：

const addGroupMembers = Object.entries(myObject).filter(entry => 
mySet.has(entry[0])).reduce((accum, [k, v]) => {
accum[k] = v;
return accum;
}, {});

uj5u.com熱心網友回復：

您可以myObject使用Object.entries()thenSet.has()與 with 一起使用轉換為條目陣列Array.filter()，最后使用Object.fromEntries()將過濾后的條目陣列轉換回物件：

const myObject = {
    "-Lz8YxHiwp8QZW3TqAFn": { first: "Breanna", last: "Blah" },
    "-Lz8YxHqQXWoaGOFRLrO": { first: "Joshua", last: "Blah" },
    "-Lz8YxHsMItaaTVNyQRE": { first: "Joziah", last: "Blah" },
    "-Lz8YxHwuVBMWl0Go6C5": { first: "Lino", last: "Blah" },
    "-Lz8YxHy0S-QkDaE1PkX": { first: "Rebecca", last: "Blah" },
    "-Lz8YxI5IItUiXX6rFn_": { first: "Rosario", last: "Blah" },
    "-Lz8YxIB_YTBF8liL855": { first: "Alissa", last: "Blah" },
};

const mySet = new Set([
    "-Lz8YxMp-V0TfiwrkM49",
    "-Lz8YxNQP2WkkO0qpkRJ",
    "-Lz8YxHy0S-QkDaE1PkX",
    "-MmFNgjyopU3E8z5g-zU",
    "-Lz8YxLVi_uZp_RkcRIH",
    "-MuEgimJOIbPw3GyKBJ3",
    "-Lz8YxOFpVHx2xPI1mUu",
    "-Lz8YxJ-_wuk8bmEyvGT",
    "-Lz8YxKj5WXY1oNwylQ4",
    "-Lz8YxN87U1YM6_fKgq1",
    "-Lz8YxOI4qszJvZhrSde",
    "-Lz8YxI5IItUiXX6rFn_",
]);

const myObjectFiltered = Object.fromEntries(
    Object.entries(myObject).filter(([key]) => mySet.has(key))
);

console.log(myObjectFiltered);

uj5u.com熱心網友回復：

這個問題對我來說有點令人困惑抱歉，但我希望這能有所幫助：

基本上，在 javascript 中，要直接更改現有物件以洗掉元素，而不是創建更改后的副本，您可以使用：

delete someObject[key]

它將直接更改您的物件，這將適用于參考它的所有內容。

因此 ：

const myObject = {
    "-Lz8YxHiwp8QZW3TqAFn":  {
    "first": "Breanna",
        "last": "Blah",
},
"-Lz8YxHqQXWoaGOFRLrO": {
    "first": "Joshua",
        "last": "Blah",
},
"-Lz8YxHsMItaaTVNyQRE": {
    "first": "Joziah",
        "last": "Blah",
},
"-Lz8YxHwuVBMWl0Go6C5": {
    "first": "Lino",
        "last": "Blah",
},
"-Lz8YxHy0S-QkDaE1PkX": {
    "first": "Rebecca",
        "last": "Blah",
},
"-Lz8YxI5IItUiXX6rFn_": {
    "first": "Rosario",
        "last": "Blah",
},
"-Lz8YxIB_YTBF8liL855": {
    "first": "Alissa",
        "last": "Blah",
}
}

const mySet = [
    "-Lz8YxMp-V0TfiwrkM49",
    "-Lz8YxNQP2WkkO0qpkRJ",
    "-Lz8YxHy0S-QkDaE1PkX",
    "-MmFNgjyopU3E8z5g-zU",
    "-Lz8YxLVi_uZp_RkcRIH",
    "-MuEgimJOIbPw3GyKBJ3",
    "-Lz8YxOFpVHx2xPI1mUu",
    "-Lz8YxJ-_wuk8bmEyvGT",
    "-Lz8YxKj5WXY1oNwylQ4",
    "-Lz8YxN87U1YM6_fKgq1",
    "-Lz8YxOI4qszJvZhrSde",
    "-Lz8YxI5IItUiXX6rFn_",
]

for (const i in myObject)
    if (!mySet.includes(i))
        delete myObject[i];

console.log(myObject);

一個例子。抱歉更改語法，但看起來很奇怪，希望對您有所幫助。

uj5u.com熱心網友回復：

使用Array#reduce和計算的屬性名稱：

const yourObject={"-Lz8YxHiwp8QZW3TqAFn":{first:"Breanna",last:"Blah"},"-Lz8YxHqQXWoaGOFRLrO":{first:"Joshua",last:"Blah"},"-Lz8YxHsMItaaTVNyQRE":{first:"Joziah",last:"Blah"},"-Lz8YxHwuVBMWl0Go6C5":{first:"Lino",last:"Blah"},"-Lz8YxHy0S-QkDaE1PkX":{first:"Rebecca",last:"Blah"},"-Lz8YxI5IItUiXX6rFn_":{first:"Rosario",last:"Blah"},"-Lz8YxIB_YTBF8liL855":{first:"Alissa",last:"Blah"}};

const yourSet = ["-Lz8YxMp-V0TfiwrkM49", "-Lz8YxNQP2WkkO0qpkRJ", "-Lz8YxHy0S-QkDaE1PkX", "-MmFNgjyopU3E8z5g-zU", "-Lz8YxLVi_uZp_RkcRIH", "-MuEgimJOIbPw3GyKBJ3", "-Lz8YxOFpVHx2xPI1mUu", "-Lz8YxJ-_wuk8bmEyvGT", "-Lz8YxKj5WXY1oNwylQ4", "-Lz8YxN87U1YM6_fKgq1", "-Lz8YxOI4qszJvZhrSde", "-Lz8YxI5IItUiXX6rFn_"];

let result = yourSet.reduce((acc, e, i) => {
  if (Object.keys(yourObject).includes(e))
    acc = { ...acc, [e]: yourObject[e]}
  return acc
}, {})

console.log(result)

標籤：javascript javascript 对象

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