One Pager Cheat Sheet
- The text requests the implementation of a shuffle method that accepts an
arrayas a parameter and generates a random permutation of its elements. - The article describes the process of creating a shuffling algorithm that takes an array and randomizes its order by visiting each element in the array and exchanging it with another randomly chosen element using a
swapping technique, ensuring that every potential arrangement of elements is likely. - The shuffling function in
JavaScriptworks by looping through an array, computing a random index, and swapping elements, introducing randomness to rearrange the elements.
This is our final solution.
To visualize the solution and step through the below code, click Visualize the Solution on the right-side menu or the VISUALIZE button in Interactive Mode.
xxxxxxxxxx27
// Shuffle function implementation - fill in your code!function shuffle(arr) { for (let i = 0; i < arr.length; i++) { const j = i + Math.floor(Math.random() * (arr.length - i)); [arr[i], arr[j]] = [arr[j], arr[i]]; }}const arr = [1, 2, 3, 4];const permutations = [ [1, 2, 3, 4], [1, 2, 4, 3], [1, 3, 2, 4], [1, 3, 4, 2], [1, 4, 2, 3], [1, 4, 3, 2], [2, 1, 3, 4], [2, 1, 4, 3], [2, 3, 1, 4], [2, 3, 4, 1], [2, 4, 1, 3], [2, 4, 3, 1], [3, 1, 2, 4], [3, 1, 4, 2], [3, 2, 1, 4], [3, 2, 4, 1], [3, 4, 1, 2], [3, 4, 2, 1], [4, 1, 2, 3], [4, 1, 3, 2], [4, 2, 1, 3], [4, 2, 3, 1], [4, 3, 1, 2], [4, 3, 2, 1]];// Shuffle the arrayshuffle(arr);// Validate the shuffled arrayconst isValidPermutation = permutations.some(permutation => JSON.stringify(permutation) === JSON.stringify(arr));if (isValidPermutation) { console.log('The shuffled array is a valid permutation:', arr);} else { console.log('Something went wrong! The shuffled array does not match any of the valid permutations.');}OUTPUT
:001 > Cmd/Ctrl-Enter to run, Cmd/Ctrl-/ to comment
You're doing a wonderful job. Keep going!
If you had any problems with this tutorial, check out the main forum thread here.
