23 lines
657 B
Markdown
23 lines
657 B
Markdown
---
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title: Initialize 2D array
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tags: array
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cover: cloudy-rock-formation
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firstSeen: 2017-12-19T23:38:18+02:00
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lastUpdated: 2020-10-20T23:02:01+03:00
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---
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Initializes a 2D array of given width and height and value.
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- Use `Array.from()` and `Array.prototype.map()` to generate `h` rows where each is a new array of size `w`.
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- Use `Array.prototype.fill()` to initialize all items with value `val`.
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- Omit the last argument, `val`, to use a default value of `null`.
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```js
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const initialize2DArray = (w, h, val = null) =>
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Array.from({ length: h }).map(() => Array.from({ length: w }).fill(val));
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```
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```js
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initialize2DArray(2, 2, 0); // [[0, 0], [0, 0]]
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```
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