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Javascript: Shuffle an Array

Learn how to shuffle an array using JavaScript. This snippet demonstrates the Fisher-Yates Shuffle algorithm for randomizing the order of array elements.

Shuffling an array is a common task in programming, especially in applications that require randomization, such as games, quizzes, or data sampling. This snippet demonstrates how to shuffle an array in JavaScript using the Fisher-Yates (Knuth) Shuffle algorithm. The Fisher-Yates Shuffle is an efficient and unbiased algorithm for randomizing the order of elements in an array.

In this example, we define a function shuffleArray that takes an array as an argument. The function iterates through the array from the last element to the first, swapping each element with a randomly selected element that comes before it (or with itself). This ensures that each element has an equal probability of ending up in any position.

The shuffleArray function uses a for loop and the Math.random function to generate random indices for swapping elements. The temporary variable temp is used to hold the value of the current element during the swap process. This technique guarantees that the array is shuffled in place without requiring additional memory.

Shuffling an array is useful in various scenarios, such as creating random sequences, randomizing questions in a quiz, selecting random samples from a dataset, and more. Understanding how to implement the Fisher-Yates Shuffle algorithm can help you achieve fair and unbiased randomization in your applications.

The Fisher-Yates Shuffle algorithm is preferred over other shuffling methods because it provides a uniform distribution of permutations. This ensures that every possible arrangement of the array elements is equally likely, making it a reliable choice for randomization tasks.

Snippet Code

Use Cases

  • Creating random sequences
  • Randomizing quiz questions
  • Selecting random samples
  • Shuffling playlists
  • Improving game logic