How to get random items from an array with no repeat?
I have an array of elements like
var a = ["Mango", "Orange", "Banana", "Apple", "Grapes", "Berry", "Peach"]
I want to get 3 random items from array a
var random = ["Banana", "Berry", "Peach"]
var a = ["Mango","Orange","Banana","Apple","Grapes","Berry","Peach"];
function searchRandom(count, arr){
let answer = [], counter = 0;
while(counter < count){
let rand = arr[Math.floor(Math.random() * arr.length)];
if(!answer.some(an => an === rand)){
answer.push(rand);
counter++;
}
}
return answer;
}
console.log(searchRandom(3,a))Making it flexible to support any count you want and ensured uniqueness
var a = ["Mango","Orange","Banana","Apple","Grapes","Berry","Peach"]
var res = a.sort(function() {
return 0.5 - Math.random();
});
console.log(res.slice(a,3))
.sort sorts the array in place, modifying the original one. You should make a copy and sort that one if you don't want any side effect.This should work without any duplicates:
const a = ["Mango","Orange","Banana","Apple","Grapes","Berry","Peach"]
const b = a.slice()
const newArr = [];
for(let i= 0; i<3; i++){
let arr = b[Math.floor(Math.random()*b.length)];
let index = b.indexOf(arr);
b.splice(index, 1 );
newArr.push(arr)
}
console.log(newArr)
Try this:-
var a = ["Mango","Orange","Banana","Apple","Grapes","Berry","Peach"]
b = _.shuffle(a).slice(0,5);
console.log(b);
i would like to improve the Willem van der Veen's answer because his code might return undefined. It stems from the fact that the arrayClone takes out the random item but random number still in the range of the previous index length. Hence, the solution is we have to decrease the arrayClone's length too:
const array = [0, 1 ,2 ,3 ,4, 5, 6, 7, 8 , 9]
const arrayClone = array.slice()
let arrayLength = array.length
let newArray = []
for ( let i = 0; i < 5; i++) {
let arr = arrayClone[Math.floor(Math.random() * arrayLength)]
arrayLength--
let index = arrayClone.indexOf(arr)
arrayClone.splice(index, 1)
newArray.push(arr)
}
console.log(newArray)
