# JavaScript: Count the occurrences of a value in an array

## JavaScript fundamental (ES6 Syntax): Exercise-70 with Solution

Write a JavaScript program to count a value in an array.

• Use Array.prototype.reduce() to increment a counter each time the specific value is encountered inside the array.

Sample Solution:

JavaScript Code:

``````//#Source https://bit.ly/2neWfJ2
// Define a function 'countOccurrences' that counts the number of occurrences of a value in an array.
const countOccurrences = (arr, val) =>
arr.reduce((a, v) => (v === val ? a + 1 : a), 0);

// Example usages:
console.log(countOccurrences([1, 1, 2, 1, 2, 3], 1)); // Output: 3
console.log(countOccurrences([1, 1, 2, 1, 2, 3], 2)); // Output: 2
console.log(countOccurrences([1, 1, 2, 1, 2, 3], 3)); // Output: 1
```
```

Output:

```3
2
1
```

Visual Presentation:

Flowchart:

Live Demo:

See the Pen javascript-basic-exercise-70-1 by w3resource (@w3resource) on CodePen.

Improve this sample solution and post your code through Disqus

What is the difficulty level of this exercise?

Test your Programming skills with w3resource's quiz.

﻿