Counts the occurrences of a value in an array.
Array.prototype.reduce() to increment a counter each time the specific value is encountered inside the array.const countOccurrences = (arr, val) => arr.reduce((a, v) => (v === val ? a + 1 : a), 0); countOccurrences([1, 1, 2, 1, 2, 3], 1); // 3
Learn how to group and count the values of a JavaScript array using simple array methods.
Easily remove duplicates from a JavaScript array using the built-in Set object, and learn a few other tricks along the way.
Group array elements into two or more arrays arrays, depending on the provided function's return value.
Ever wanted to initialize an array with a sequence of generated values? Here's a few ways to do it.