28 lines
696 B
Markdown
28 lines
696 B
Markdown
---
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title: mapValues
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tags: object,intermediate
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firstSeen: 2018-01-11T20:33:14+02:00
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lastUpdated: 2020-10-21T21:54:53+03:00
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---
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Maps the values of an object using the provided function, generating a new object with the same keys.
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- Use `Object.keys()` to iterate over the object's keys.
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- Use `Array.prototype.reduce()` to create a new object with the same keys and mapped values using `fn`.
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```js
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const mapValues = (obj, fn) =>
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Object.keys(obj).reduce((acc, k) => {
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acc[k] = fn(obj[k], k, obj);
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return acc;
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}, {});
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```
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```js
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const users = {
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fred: { user: 'fred', age: 40 },
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pebbles: { user: 'pebbles', age: 1 }
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};
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mapValues(users, u => u.age); // { fred: 40, pebbles: 1 }
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```
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