Shuffle an Array in JavasScript
Feb 25, 2022
To properly shuffle an array in JavaScript, use the Fisher-Yates shuffle algorithm. The algorithm loops through each element in the array and swaps it with a random element in the array as shown below.
let array = [1, 2, 3, 4, 5];
for(let i = array.length - 1; i >= 1; i--) {
let j = Math.floor(Math.random() * (i + 1)); // 0 <= j <= i
let temp = array[j];
array[j] = array[i];
array[i] = temp;
}
console.log(array);To do it in the opposite direction, do the following:
let array = [1, 2, 3, 4, 5];
for(let i = 0; i <= array.length - 2; i++) {
let j = Math.floor(Math.random() * array.length); // i <= j < array.length
let temp = array[i];
array[i] = array[j];
array[j] = temp;
}
console.log(array);
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