index of max value in array javascript 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: max value in array javascript

// For large data, it's better to use reduce. Supose arr has a large data in this case:
const arr = [1, 5, 3, 5, 2];
const max = arr.reduce((a, b) => { return Math.max(a, b) });

// For arrays with relatively few elements you can use apply: 
const max = Math.max.apply(null, arr);

// or spread operator:
const max = Math.max(...arr);

Example 3: 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

Example 4: how to return the max and min of an array in javascript

function minMax(arr) {
  return [Math.min(...arr), Math.max(...arr)];
}

Example 5: javascript index of biggest number

arr.indexOf(Math.max(...arr))