28 lines
679 B
Markdown
28 lines
679 B
Markdown
---
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title: indexOn
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tags: array,object,intermediate
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firstSeen: 2021-06-27T05:00:00-04:00
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---
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Creates an object from an array, using the specified key and excluding it from each value.
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- Use `Array.prototype.reduce()` to create an object from `arr`.
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- Use object destructuring to get the value of the given `key` and the associated `data` and add the key-value pair to the object.
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```js
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const indexOn = (arr, key) =>
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arr.reduce((obj, v) => {
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const { [key]: id, ...data } = v;
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obj[id] = data;
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return obj;
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}, {});
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```
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```js
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indexOn([
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{ id: 10, name: 'apple' },
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{ id: 20, name: 'orange' }
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], 'id');
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// { '10': { name: 'apple' }, '20': { name: 'orange' } }
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```
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