If you're a Ruby programmer, chances are you've encountered a situation where you need to generate a list of unique random numbers. Whether it's for a game, a statistical analysis, or any other application, having a way to generate a list of N unique random numbers can be incredibly useful. In this article, we'll explore different methods for generating a list of unique random numbers in Ruby.
Before we dive into the code, let's define what we mean by "unique" random numbers. A unique random number is a number that is not repeated in a given list. For example, if we have a list of 10 random numbers, each number should only appear once in that list.
Method 1: Using the sample method
One of the simplest ways to generate a list of N unique random numbers in Ruby is by using the sample method. This method is available on the Array class and allows us to select a random number of elements from an array. To use this method, we first need to create an array of numbers from which we want to select. We can do this using the splat operator, which allows us to expand a range of numbers into an array.
For example, if we want to generate a list of 10 unique random numbers between 1 and 100, we can use the following code:
```
numbers = *(1..100)
list = numbers.sample(10)
```
The sample method takes in an argument that specifies the number of random elements we want to select from the array. In this case, we want to select 10 random numbers, so we pass in the argument "10". The resulting list will contain 10 unique random numbers from 1 to 100.
Method 2: Using the shuffle and take methods
Another way to generate a list of unique random numbers in Ruby is by using the shuffle method in combination with the take method. The shuffle method randomly shuffles the elements of an array, and the take method allows us to select a specific number of elements from the beginning of the array.
To use this method, we first need to create an array of numbers similar to the previous method. Then, we shuffle the array and take the first N elements to generate our list of unique random numbers.
```
numbers = *(1..100)
list = numbers.shuffle.take(10)
```
This method also allows us to specify the range of numbers we want to select from by changing the numbers in the array.
Method 3: Using the rand and uniq methods
Lastly, we can use the combination of the rand and uniq methods to generate a list of unique random numbers in Ruby. The rand method returns a random number within a specified range, and the uniq method removes any duplicate elements from an array.
To use this method, we first generate an array of random numbers using the rand method, and then use the uniq method to remove any duplicates. However, this method does not guarantee that the list will contain N elements, as the uniq method will keep removing duplicates until there are no more left. To ensure that we have a list of N unique random numbers, we can use a loop to check the length of the array and keep generating numbers until the length matches our desired number.
```
list = []
while list.length < 10
list << rand(1..100)
end
list = list.uniq
```
In conclusion, there are multiple ways to generate a list of N unique random numbers in Ruby. Whether we use the sample method, the shuffle and take methods, or the rand and uniq methods, we can easily generate a list of random numbers for any purpose. Experiment with these methods and see which one works best for your specific use case. Happy coding!
