Find the n min or max elements in a JavaScript array

We've previously covered finding the minimum and maximum value in a numeric array, but what if you need to find the n minimum or maximum values? Turns out it's almost as easy.

For either one of the operations, we'll first need to sort the array in ascending or descending order. This can be done using Array.prototype.sort() and the appropriate comparator function. However, we'll need to create a shallow clone of the array first using the spread operator (...) to avoid mutating the original array.

Then, we can use Array.prototype.slice() to get the first n elements of the sorted array. If n is not provided, we'll get the first element of the array. If n is greater than or equal to the length of the array, we'll get the original array back.

const minN = (arr, n = 1) => [...arr].sort((a, b) => a - b).slice(0, n);
const maxN = (arr, n = 1) => [...arr].sort((a, b) => b - a).slice(0, n);

minN([1, 2, 3]); // [1]
minN([1, 2, 3], 2); // [1, 2]
maxN([1, 2, 3]); // [3]
maxN([1, 2, 3], 2); // [3, 2]