How to get n no elements randomly from an array

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I am working on 'how to access elements randomly from an array in javascript'. I found many links regarding this. Like: Get random item from JavaScript array

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

Question: But in this we can choose only one item from the array.If we want more than one elements then how can we achieve this.So please just from this statement how can we get more than one elements from an array.

Try this non-destructive (and fast) function:

function getRandom(arr, n) {
    var result = new Array(n),
        len = arr.length,
        taken = new Array(len);
    if (n > len)
        throw new RangeError("getRandom: more elements taken than available");
    while (n--) {
        var x = Math.floor(Math.random() * len);
        result[n] = arr[x in taken ? taken[x] : x];
        taken[x] = --len in taken ? taken[len] : len;
    }
    return result;
}

Selecting 6 random elements from an array, the click of a button. I want to create a function which will select 6 random elements from an array of 16 elements and return another array of the… Selecting 6 random elements from an array · Get Help · JavaScript · learn-arrays The code below only returns 1 element, not 6 elements. I'm unable to see  This example builds a generic extension method that lets you easily select N random objects from an array. For example, it lets you select 5 items from an array holding 10 names. Picking one random item from an array is easy. Just use a Random object as demonstrated by the example Select random objects from an array in C#.

Just two lines :

// Shuffle array
const shuffled = array.sort(() => 0.5 - Math.random());

// Get sub-array of first n elements after shuffled
let selected = shuffled.slice(0, n);

DEMO:

How to select a random element from array in JavaScript , The task is to select the random element from the array using JavaScript. Approach 1: How to get N options from the <select> element using JQuery? How to  When you instantiate Shuffler, give it your array as a parameter. It will create a copy of the array and every time next() is called it will return a random element from a copy and remove it from the copy array so that no repeats are possible.

create a funcion which does that:

var getMeRandomElements = function(sourceArray, neededElements) {
    var result = [];
    for (var i = 0; i < neededElements; i++) {
        result.push(sourceArray[Math.floor(Math.random()*sourceArray.length)]);
    }
    return result;
}

you should also check if the sourceArray has enough elements to be returned. and if you want unique elements returned, you should remove selected element from the sourceArray.

How to get a random value from a JavaScript array, How to get a random value from a JavaScript array Of course, we can use this function to pick any random value from an array, not only colors. returns us an element of the array at the random index, just like we wanted. If you are picking random array elements that need to be unpredictable, you should use java.security.SecureRandom rather than Random. That ensures that if somebody knows the last few picks, they won't have an advantage in guessing the next one. If you are looking to pick a random number from an Object array using generics, you could define a

Getting 5 random items without changing the original array:

const n = 5;
const sample = items
  .map(x => ({ x, r: Math.random() }))
  .sort((a, b) => a.r - b.r)
  .map(a => a.x)
  .slice(0, n);

(Don't use this for big lists)

Playing with array in javascript using Math.random(), Let's write a function to return a random element from an array. We can use Math.​random() to generate a number between 0–1 (inclusive of 0, but not 1)  I needed to return a random element of an array using powershell. I have used this method while building simple wireless passwords for a company. This is a simplified version, first lets create the array with Blue and Green in it.

JavaScript array: Randomly arrange or shuffle an array, By using our site, you acknowledge that you have read and understood our Privacy Policy. Write a JavaScript program to shuffle an array. While there are elements in the array while (ctr > 0) { // Pick a random index index = Math.​floor(Math.random() Create a n-dimensional array with given value. I have an array with numbers and I want to get random elements from this array. For example: {0,1,4,6,8,2}. I want to select 6 and put this number in another array, and the new array will have the value {6,.}. I use random.next(0, array.length), but this gives a random number of the length and I need the random array numbers.

How to get multiple, random, unique elements from a JavaScript array, How to get multiple, random, unique elements from a JavaScript array. By Alvin Alexander. Last updated: April 18, 2018. As a note to self, this JavaScript code  By doing this way, you will get all the numbers in the particular range but in a random order. But you can use random.sample to get the number of elements you need, from a range of numbers like this print random.sample(range(numLow, numHigh), 3)

Select Random Item from an Array, var randomItem = myArray[Math.floor(Math.random()*myArray.length)]; were algorithmically generated and displayed here without any load on my They have courses on all the most important front-end technologies, from  If you need to get more than one item randomly, you can pass that as a second argument in underscore: // will return two items randomly from the array using underscore _.sample( ['January', 'February', 'March'], 2); or use the _.sampleSize method in lodash: // will return two items randomly from the array using lodash _.sampleSize( ['January

Java, Picking a random List element is a very basic operation but not so In order to get a random item from a List instance, you need to generate a random index number and then fetch an item List<Integer> givenList = Arrays. In order to generate random array of integers in Java, we use the nextInt() method of the java.util.Random class. This returns the next random integer value from this random number generator sequence. Declaration − The java.util.Random.nextInt() method is declared as follows −.

Comments
  • Just execute it multiple times?
  • From this statement can we do this?? Loop generating duplicates.
  • From that exact statement you can't get more than one element.
  • Ah, you should've said that you want no duplicates. Then check Unique random numbers in O(1)? and my answer at Generate unique number within range (0 - X), keeping a history to prevent duplicates
  • I made a JsPerf to test some of the solutions here. @Bergi's seems to be the best in general, while mine works better if you need many elements from the array. jsperf.com/k-random-elements-from-array
  • working nice with jQuery elements, very nice, my choice for randomizing elements.
  • The author said (in the comments) that he wants to avoid duplicates. This produces duplicates.
  • @SamuelBolduc: I've seen that, but he should've put that in the question in the first place. Editing the question now would invalidate the answers. If you're looking for a non-repeating random generator, have a look here
  • Hey man, I just wanted to say I spent about ten minutes appreciating the beauty of this algorithm.
  • @cbdev420 Yes, it's just a (partial) fisher-yates shuffle
  • Very nice! One liner also of course possible: let random = array.sort(() => .5 - Math.random()).slice(0,n)
  • Genius! Elegant, short and simple, fast, using built-in functionality.
  • It's nice, but is far from random. The first item has many more chances to get picked than the last one. See here why: stackoverflow.com/a/18650169/1325646