21 lines
468 B
Markdown
21 lines
468 B
Markdown
---
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title: Count occurrences
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tags: array
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cover: dark-leaves-4
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firstSeen: 2017-12-17T17:55:51+02:00
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lastUpdated: 2020-10-18T23:04:45+03:00
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---
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Counts the occurrences of a value in an array.
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- Use `Array.prototype.reduce()` to increment a counter each time the specific value is encountered inside the array.
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```js
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const countOccurrences = (arr, val) =>
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arr.reduce((a, v) => (v === val ? a + 1 : a), 0);
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```
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```js
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countOccurrences([1, 1, 2, 1, 2, 3], 1); // 3
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```
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