Скачать или смотреть Generate a Random Number Excluding Array Elements

Discover how to create a random number in JavaScript that is both unique from an array and limited to a certain range.
---
This video is based on the question https://stackoverflow.com/q/62354692/ asked by the user 'Diego Monsalve' ( https://stackoverflow.com/u/9549867/ ) and on the answer https://stackoverflow.com/a/62354852/ provided by the user 'user120242' ( https://stackoverflow.com/u/120242/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions.

Visit these links for original content and any more details, such as alternate solutions, latest updates/developments on topic, comments, revision history etc. For example, the original title of the Question was: Create random number different from the numbers inside an array

Also, Content (except music) licensed under CC BY-SA https://meta.stackexchange.com/help/l...
The original Question post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license, and the original Answer post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license.

If anything seems off to you, please feel free to write me at vlogize [AT] gmail [DOT] com.
---
How to Generate a Random Number Excluding Array Elements in JavaScript

Generating random numbers is a common requirement in programming, especially in games or applications that require unpredictability. But what happens when you have an array of numbers, and you need to generate a random number that is not included in that array? In this guide, we will explore how to solve this problem using JavaScript.

The Problem Statement

Let's imagine you have an array of numbers, for example, [2, 8, 5, 6]. You want to generate a random number that:

Is different from the numbers in the array.

Does not exceed a specific maximum value, in this case, 100.

This can be quite challenging, especially if you're not sure how to avoid generating numbers that already exist in your array. Fortunately, JavaScript provides tools that make this process straightforward.

The Solution

We will use a combination of JavaScript's Set() and random number generation techniques to achieve this. Here’s a step-by-step breakdown of how we can implement this solution.

Step 1: Use a Set for Unique Values

Using a Set is an effective way to manage unique values. Unlike arrays, sets automatically ignore duplicate values, making them perfect for our needs.

[[See Video to Reveal this Text or Code Snippet]]

Step 2: Create a Random Number Generator Function

The core of our solution lies in a function that generates a random number while checking against the numbers in our set. Here’s how the function can be structured:

[[See Video to Reveal this Text or Code Snippet]]

In this function, we generate a random number (rand). If it already exists in our exclude set (which contains the numbers from our original array), we loop until we find a new number.

Step 3: Generate Random Numbers

Now that we have our function, we can simply call it as needed. Each call to getRandom() will provide a new number that adheres to the restrictions we've set.

[[See Video to Reveal this Text or Code Snippet]]

Summary

To summarize, generating a random number that is not part of a specific array is achievable in JavaScript by following these steps:

Create a Set from the array to manage existing numbers.

Develop a random number generator function that loops until a unique value is found.

Call the function as needed to receive unique random numbers.

Feel free to use the code provided in your own projects. This can serve as a foundation for many applications where random, unique values are required, particularly in games or random selection scenarios!

Thank you for reading, and happy coding!