33 lines
811 B
Markdown
33 lines
811 B
Markdown
---
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title: Map an array to an object
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tags: array,object
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author: chalarangelo
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cover: metro-tunnel
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firstSeen: 2023-02-04T05:00:00-04:00
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---
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Maps an object array to an object, using the provided mapping functions.
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- Use `Array.prototype.reduce()` to map the array to an object.
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- Use `mapKey` to map the keys of the object and `mapValue` to map the values.
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```js
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const objectify = (arr, mapKey, mapValue = i => i) =>
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arr.reduce((acc, item) => {
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acc[mapKey(item)] = mapValue(item);
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return acc;
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}, {});
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```
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```js
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const people = [ { name: 'John', age: 42 }, { name: 'Adam', age: 39 } ];
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objectify(people, p => p.name.toLowerCase());
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// { john: { name: 'John', age: 42 }, adam: { name: 'Adam', age: 39 } }
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objectify(
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people,
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p => p.name.toLowerCase(),
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p => p.age
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);
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// { john: 42, adam: 39 }
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```
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