首頁猿問對象中的深度收集

對象中的深度收集

JavaScript

繁星淼淼 2022-10-27 10:49:23

我在下面有一個 JSON 對象：{ "JOHN": { "class": "ABC", "meta": { "Math": [ { "id": "math_point", "name": "Math Point", "type": "comparable" }, { "id": "math_switch", "name": "Math Switch", "type": "switch" } ], "History": [ { "id": "history_point", "name": "Math Point", "type": "comparable" }, { "id": "history_switch", "name": "Math Switch", "type": "switch" } ] } }, "BOB": { "class": "DFE", "meta": { "Math": [ { "id": "math_point", "name": "Math Point", "type": "comparable" }, { "id": "math_switch", "name": "Math Switch", "type": "switch" } ], "Biology": [ { "id": "biology_point", "name": "Biology Point", "type": "comparable" }, { "id": "biology_switch", "name": "Biology Switch", "type": "switch" } ] } }}使用 Lodash 或 VanilaJS 的最佳方式返回（唯一id）：[ { "id": "math_point", "name": "Math Point", "type": "comparable" }, { "id": "math_switch", "name": "Math Switch", "type": "switch" }, { "id": "history_point", "name": "Math Point", "type": "comparable" }, { "id": "history_switch", "name": "Math Switch", "type": "switch" },

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4 回答

慕尼黑8549860

TA貢獻1818條經(jīng)驗獲得超11個贊

您可以使用提取數(shù)組 Object.values。將它們展平為一個數(shù)組，然后使用一個 Map，鍵為id，將其減少為一組唯一的值：

let obj = {"JOHN": {"class": "ABC","meta": {"Math": [{"id": "math_point","name": "Math Point","type": "comparable"},{"id": "math_switch","name": "Math Switch","type": "switch"}],"History": [{"id": "history_point","name": "Math Point","type": "comparable"},{"id": "history_switch","name": "Math Switch","type": "switch"}]}},"BOB": {"class": "DFE","meta": {"Math": [{"id": "math_point","name": "Math Point","type": "comparable"},{"id": "math_switch","name": "Math Switch","type": "switch"}],"Biology": [{"id": "biology_point","name": "Biology Point","type": "comparable"},{"id": "biology_switch","name": "Biology Switch","type": "switch"}]}}};

let arr = Array.from(new Map(

Object.values(obj)

.flatMap(({meta}) => Object.values(meta))

.flat()

.map(o => [o.id, o])

).values());

console.log(arr);

反對回復(fù) 2022-10-27

慕桂英4014372

TA貢獻1871條經(jīng)驗獲得超13個贊

您首先需要將 JSON 解析為 javascript 對象，然后您可以使用臨時對象來保存所有唯一鍵及其對應(yīng)的對象。之后，您可以使用Object.values()函數(shù)從臨時對象中提取對象

const obj = {"JOHN": {"class": "ABC","meta": {"Math": [{"id": "math_point","name": "Math Point","type": "comparable"},{"id": "math_switch","name": "Math Switch","type": "switch"}],"History": [{"id": "history_point","name": "Math Point","type": "comparable"},{"id": "history_switch","name": "Math Switch","type": "switch"}]}},"BOB": {"class": "DFE","meta": {"Math": [{"id": "math_point","name": "Math Point","type": "comparable"},{"id": "math_switch","name": "Math Switch","type": "switch"}],"Biology": [{"id": "biology_point","name": "Biology Point","type": "comparable"},{"id": "biology_switch","name": "Biology Switch","type": "switch"}]}}};

const temp = {};

Object.values(obj).forEach(({meta}) => {

Object.values(meta).flat().forEach(o => (temp[o.id] = o));

});

const result = Object.values(temp);

console.log(result);

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

反對回復(fù) 2022-10-27

函數(shù)式編程

TA貢獻1807條經(jīng)驗獲得超9個贊

由于這個問題被標(biāo)記為 lodash 怎么樣只是簡單地使用這個：

_.flatMapDeep(input, e => Object.values(e.meta))

它更具可讀性。

由于您只對每個元對象的值感興趣。每個元對象的所有值都是一個數(shù)組（值，而不是鍵），您基本上是在查看這些數(shù)組的內(nèi)容，就是這樣。所以只需簡單地把它們都拿走，然后用 lodash 壓平。

讓我們有一個片段：

let input = {"JOHN":{"class":"ABC","meta":{"Math":[{"id":"math_point","name":"Math Point","type":"comparable"},{"id":"math_switch","name":"Math Switch","type":"switch"}],"History":[{"id":"history_point","name":"Math Point","type":"comparable"},{"id":"history_switch","name":"Math Switch","type":"switch"}]}},"BOB":{"class":"DFE","meta":{"Math":[{"id":"math_point","name":"Math Point","type":"comparable"},{"id":"math_switch","name":"Math Switch","type":"switch"}],"Biology":[{"id":"biology_point","name":"Biology Point","type":"comparable"},{"id":"biology_switch","name":"Biology Switch","type":"switch"}]}}},

res = _.flatMapDeep(input, e => Object.values(e.meta));

console.log(res);

反對回復(fù) 2022-10-27

蠱毒傳說

TA貢獻1895條經(jīng)驗獲得超3個贊

let arr = Object.values(obj)

let ids = [];

for(let i = 0; i < arr.length; i++){

for(let j = 0; j < Object.values(arr[i].meta).length; j++){

for(let k = 0; k < Object.values(arr[i].meta)[j].length; k++){

ids.push(Object.values(arr[i].meta)[j][k].id)

}

console.log([...new Set(ids)])

這將返回所有唯一 ID

反對回復(fù) 2022-10-27

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對象中的深度收集

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