R Lang

# Reversing an Array of Numbers in R: How to Change the Order of Elements2 min read

In programming, it is often necessary to manipulate arrays and change the order of elements. In this article, we will explore how to reverse an array of numbers using the R programming language. Reversing an array means changing the order of its elements so that the last element becomes the first, the second-to-last element becomes the second, and so on.

To reverse an array of numbers in R, we can make use of the `rev()` function. This function takes an array as input and returns a new array with the elements in reversed order. Let’s take a look at a simple example:

In the above code, we start by creating an array of numbers using the `c()` function. Then, we use the `rev()` function to reverse the array and store the result in a new variable called `reversed_array`. Finally, we print both the original and reversed arrays using the `cat()` function.

When you run the above code, you will see the following output:

As you can see, the elements of the original array have been reversed, and the last element `5` is now the first element in the reversed array.

Here’s the alternative method with the explanations:

In the code above, we begin by creating an array of numbers using the `c()` function. The alternative approach to reversing the array involves using two indices, `start_index` and `end_index`, starting from the first and last indices respectively.

Within the while loop, we swap the elements at the `start_index` and `end_index` positions by using a temporary variable `temp`. The value at `start_index` is assigned to `temp`, then the value at `end_index` is assigned to `start_index`, and finally, the value of `temp` is assigned to `end_index`. This swapping process continues until the `start_index` becomes greater than or equal to the `end_index`.

Finally, we print the reversed array using the `cat()` function. When you execute the code, you will see the following output:

This alternative method iteratively swaps elements from the start and end of the array, effectively reversing the order of the elements.