Get a random item from a JavaScript array [duplicate]

var items = Array(523, 3452, 334, 31, ..., 5346); 

How do I get random item from items?

13 Answers

var item = items[Math.floor(Math.random()*items.length)]; 

Use underscore (or loDash :)):

var randomArray = [ '#cc0000','#00cc00', '#0000cc' ]; // use _.sample var randomElement = _.sample(randomArray); // manually use _.random var randomElement = randomArray[_.random(randomArray.length-1)]; 

Or to shuffle an entire array:

// use underscore's shuffle function var firstRandomElement = _.shuffle(randomArray)[0]; 

1. solution: define Array prototype

Array.prototype.random = function () { return this[Math.floor((Math.random()*this.length))]; } 

that will work on inline arrays

[2,3,5].random() 

and of course predefined arrays

var list = [2,3,5] list.random() 

2. solution: define custom function that accepts list and returns element

function get_random (list) { return list[Math.floor((Math.random()*list.length))]; } get_random([2,3,5]) 

If you really must use jQuery to solve this problem (NB: you shouldn't):

(function($) { $.rand = function(arg) { if ($.isArray(arg)) { return arg[$.rand(arg.length)]; } else if (typeof arg === "number") { return Math.floor(Math.random() * arg); } else { return 4; // chosen by fair dice roll } }; })(jQuery); var items = [523, 3452, 334, 31, ..., 5346]; var item = jQuery.rand(items); 

This plugin will return a random element if given an array, or a value from [0 .. n) given a number, or given anything else, a guaranteed random value!

For extra fun, the array return is generated by calling the function recursively based on the array's length :)

Working demo at

Here's yet another way:

function rand(items) { // "~~" for a closest "int" return items[~~(items.length * Math.random())]; } 

Or as recommended below by @1248177:

function rand(items) { // "|" for a kinda "int div" return items[items.length * Math.random() | 0]; } 

var random = items[Math.floor(Math.random()*items.length)] 

jQuery is JavaScript! It's just a JavaScript framework. So to find a random item, just use plain old JavaScript, for example,

var randomItem = items[Math.floor(Math.random()*items.length)] 

var rndval=items[Math.floor(Math.random()*items.length)]; 

// 1. Random shuffle items items.sort(function() {return 0.5 - Math.random()}) // 2. Get first item var item = items[0] 

Shorter:

var item = items.sort(function() {return 0.5 - Math.random()})[0]; 

Even shoter (by José dB.):

let item = items.sort(() => 0.5 - Math.random())[0]; 

var items = Array(523,3452,334,31,...5346); function rand(min, max) { var offset = min; var range = (max - min) + 1; var randomNumber = Math.floor( Math.random() * range) + offset; return randomNumber; } randomNumber = rand(0, items.length - 1); randomItem = items[randomNumber]; 

credit:

Javascript Function: Random Number Generator

If you are using node.js, you can use unique-random-array. It simply picks something random from an array.

An alternate way would be to add a method to the Array prototype:

 Array.prototype.random = function (length) { return this[Math.floor((Math.random()*length))]; } var teams = ['patriots', 'colts', 'jets', 'texans', 'ravens', 'broncos'] var chosen_team = teams.random(teams.length) alert(chosen_team) 

const ArrayRandomModule = { // get random item from array random: function (array) { return array[Math.random() * array.length | 0]; }, // [mutate]: extract from given array a random item pick: function (array, i) { return array.splice(i >= 0 ? i : Math.random() * array.length | 0, 1)[0]; }, // [mutate]: shuffle the given array shuffle: function (array) { for (var i = array.length; i > 0; --i) array.push(array.splice(Math.random() * i | 0, 1)[0]); return array; } }