Find the min/max element of an Array in JavaScript

Question

How can I easily obtain the min or max element of a JavaScript Array?

Example Psuedocode:

let array = [100, 0, 50]

array.min() //=> 0
array.max()         


        

Answer 1

Iterate through, keeping track as you go.

var min = null;
var max = null;
for (var i = 0, len = arr.length; i < len; ++i)
{
    var elem = arr[i];
    if (min === null || min > elem) min = elem;
    if (max === null || max < elem) max = elem;
}
alert( "min = " + min + ", max = " + max );

This will leave min/max null if there are no elements in the array. Will set min and max in one pass if the array has any elements.

You could also extend Array with a range method using the above to allow reuse and improve on readability. See a working fiddle at http://jsfiddle.net/9C9fU/

Array.prototype.range = function() {

    var min = null,
        max = null,
        i, len;

    for (i = 0, len = this.length; i < len; ++i)
    {
        var elem = this[i];
        if (min === null || min > elem) min = elem;
        if (max === null || max < elem) max = elem;
    }

    return { min: min, max: max }
};

Used as

var arr = [3, 9, 22, -7, 44, 18, 7, 9, 15];

var range = arr.range();

console.log(range.min);
console.log(range.max);