17 lines
380 B
Markdown
17 lines
380 B
Markdown
---
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title: countOccurrences
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tags: array,intermediate
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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 you encounter the specific value inside the array.
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```js
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const countOccurrences = (arr, val) => 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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