how to get max index of array in js code example

Example 1: how to find index of max number in js

var a = [0, 21, 22, 7];
var indexOfMaxValue = a.reduce((iMax, x, i, arr) => x > arr[iMax] ? i : iMax, 0);

document.write("indexOfMaxValue = " + indexOfMaxValue); // prints "indexOfMaxValue = 2"

Example 2: js max value of array

let numbers = [4, 13, 27, 0, -5]; // Get max value of an array in Javascript

Math.max.apply(null, numbers); // returns 27