31 lines
808 B
Markdown
31 lines
808 B
Markdown
---
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title: dig
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tags: object,recursion,intermediate
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---
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Returns the target value in a nested JSON object, based on the given key.
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Use the `in` operator to check if `target` exists in `obj`.
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If found, return the value of `obj[target]`, otherwise use `Object.values(obj)` and `Array.prototype.reduce()` to recursively call `dig` on each nested object until the first matching key/value pair is found.
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```js
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const dig = (obj, target) =>
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target in obj
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? obj[target]
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: Object.values(obj).reduce((acc, val) => {
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if (acc !== undefined) return acc;
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if (typeof val === 'object') return dig(val, target);
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}, undefined);
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```
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```js
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const data = {
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level1: {
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level2: {
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level3: 'some data'
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}
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}
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};
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dig(data, 'level3'); // 'some data'
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dig(data, 'level4'); // undefined
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``` |