# Get random item from JavaScript array [duplicate]

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

How do I get random item from `items`?

``````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];
``````

If you really must use jQuery to solve this problem:

``````(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 http://jsfiddle.net/2eyQX/

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

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

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

``````get_random = function (list) {
return list[Math.floor((Math.random()*list.length))];
}

get_random([2,3,5])
``````

Here's yet another way:

``````function rand(items) {
return items[~~(items.length * Math.random())];
}
``````
``````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];
``````
``````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.

``````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;
}
}
``````

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)