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30-seconds-of-code/snippets/countOccurrences.md
Angelos Chalaris 0425ebefe7 Archive, multitagging, cleanup
Cleaned up the current snippets for consistency and minor problems, added multiple tags to most of them, archived a few.
2018-01-05 16:33:54 +02:00

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### countOccurrences
Counts the occurrences of a value in an array.
Use `Array.reduce()` to increment a counter each time you encounter the specific value inside the array.
```js
const countOccurrences = (arr, val) => arr.reduce((a, v) => (v === val ? a + 1 : a + 0), 0);
```
```js
countOccurrences([1, 1, 2, 1, 2, 3], 1); // 3
```