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對具有嵌套級別的對象數組進行分組

JavaScript

慕森卡 2023-04-14 15:14:51

我有一個表格模式數組對象，如下所示，直到 n 級。它可以是任何父母孩子的記錄var records = [ { country: "USA", state: "FLORIDA", city: "city1" }, { country: "USA", state: "FLORIDA", city: "city2" }, { country: "USA", state: "FLORIDA", city:"city3" }, { country: "USA", state: "ALASKA" }, { country: "USA", state: "ALBAMA" },]var columns = ["country","state","city"] // upto n column我需要按以下格式對第 n 級進行分組，因為可以有 n 級關系，按以下格式對記錄進行分組{ sequencer: 1, value: 'USA', loop: [ { sequencer: 1, value: 'FLORIDA', loop: [ { sequencer: 1, value: 'city1' }, { sequencer: 2, value: 'city2' }, { sequencer: 3, value: 'city3' }, ], }, { sequencer: 2, value: 'ALASKA' }, { sequencer: 3, value: 'ALBAMA' }, ],}有人可以編寫一個遞歸函數來對 n 級列對象進行分組。謝謝

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2 回答

翻過高山走不出你

TA貢獻1875條經驗獲得超3個贊

您可以通過避免不需要的循環屬性來對數據進行分組。

const

data = [{ country: "USA", state: "FLORIDA", city: "city1" }, { country: "USA", state: "FLORIDA", city: "city2" }, { country: "USA", state: "FLORIDA", city: "city3" }, { country: "USA", state: "ALASKA" }, { country: "USA", state: "ALBAMA" }],

keys = ['country', 'state', 'city'],

result = data.reduce((loop, o) => {

keys

.map(k => o[k])

.filter(Boolean)

.reduce((r, value) => {

let temp = (r.loop ??= []).find(q => q.value === value);

if (!temp) r.loop.push(temp = { sequence: r.loop.length + 1, value });

return temp;

}, { loop });

return loop;

}, []);

console.log(result);

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

反對回復 2023-04-14

慕標琳琳

TA貢獻1830條經驗獲得超9個贊

你可以寫你的transform使用flatMap和遞歸 -

const transform = ([ name, ...more ], { value, loop = [{}] }, r = {}) =>

? name === undefined

? ? ? [ r ]

? ? : loop.flatMap(t => transform(more, t, { [name]: value, ...r }))

const records =

? {sequencer:1,value:'USA',loop:[{sequencer:1,value:'FLORIDA',loop:[{sequencer:1,value:'city1'},{sequencer:2,value:'city2'},{sequencer:3,value:'city3'}]},{sequencer:2,value:'ALASKA'},{sequencer:3,value:'ALBAMA'}]}

const columns =

? ['country', 'state', 'city']

const result =

? transform(["country", "state", "city"], records)

console.log(JSON.stringify(result, null, 2))

function等同于上述表達式的語句=>-

function transform

? ( [ name, ...more ]

? , { value, loop = [{}] }

? , r = {}

? )

? { if (name === undefined)

? ? ? return [ r ]

? ? else?

? ? ? return loop.flatMap

? ? ? ? ( t =>

? ? ? ? ? ? transform

? ? ? ? ? ? ? ( more

? ? ? ? ? ? ? , t

? ? ? ? ? ? ? , { [name]: value, ...r }

? ? ? ? ? ? ? )

? ? ? ? )

? }

反對回復 2023-04-14

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對具有嵌套級別的對象數組進行分組

對具有嵌套級別的對象數組進行分組

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