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 
const countOccurrences = (arr, val) => arr.reduce((a, v) => (v === val ? a + 1 : a), 0);
console.log(countOccurrences([1, 1, 2, 1, 2, 3], 1));
console.log(countOccurrences([1, 1, 2, 1, 2, 3], 2));
console.log(countOccurrences([1, 1, 2, 1, 2, 3], 3));

Sample Output:

3
2
1

Pictorial Presentation:

Flowchart:

Live Demo:

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

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