34 lines
798 B
Markdown
34 lines
798 B
Markdown
---
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title: merge
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tags: object,array,intermediate
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---
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Creates a new object from the combination of two or more objects.
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- Use `Array.prototype.reduce()` combined with `Object.keys(obj)` to iterate over all objects and keys.
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- Use `hasOwnProperty()` and `Array.prototype.concat()` to append values for keys existing in multiple objects.
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```js
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const merge = (...objs) =>
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[...objs].reduce(
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(acc, obj) =>
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Object.keys(obj).reduce((a, k) => {
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acc[k] = acc.hasOwnProperty(k) ? [].concat(acc[k]).concat(obj[k]) : obj[k];
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return acc;
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}, {}),
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{}
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);
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```
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```js
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const object = {
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a: [{ x: 2 }, { y: 4 }],
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b: 1
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};
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const other = {
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a: { z: 3 },
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b: [2, 3],
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c: 'foo'
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};
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merge(object, other); // { a: [ { x: 2 }, { y: 4 }, { z: 3 } ], b: [ 1, 2, 3 ], c: 'foo' }
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``` |