对象中的深度收集

4回答

慕尼黑8549860

您可以使用提取数组 Object.values。将它们展平为一个数组，然后使用一个 Map，键为id，将其减少为一组唯一的值：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);

慕桂英4014372

您首先需要将 JSON 解析为 javascript 对象，然后您可以使用临时对象来保存所有唯一键及其对应的对象。之后，您可以使用Object.values()函数从临时对象中提取对象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; }

函数式编程

由于这个问题被标记为 lodash 怎么样只是简单地使用这个：_.flatMapDeep(input, e => Object.values(e.meta))它更具可读性。由于您只对每个元对象的值感兴趣。每个元对象的所有值都是一个数组（值，而不是键），您基本上是在查看这些数组的内容，就是这样。所以只需简单地把它们都拿走，然后用 lodash 压平。让我们有一个片段：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);<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.15/lodash.min.js"></script>

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