Swap

A Swap method exchanges array element values. It acts on 2 separate elements so that they both are still present but in opposite locations.

In the C# language, there is no built-in method for this purpose on most types. You have to implement a custom swap method for string characters and other types.

This example shows how to swap two characters in a string's character buffer. It also shows how to swap two elements in an array with elements of type Int32.

using System;

class Program
{
    static void Main()
    {
        // Swap characters in the string.
        string value1 = "abc";
        string swap1 = SwapCharacters(value1, 0, 1);
        Console.WriteLine(swap1);

        // Swap elements in array.
        int[] array1 = { 1, 2, 3, 4, 5 };
        SwapInts(array1, 0, 1);
        foreach (int element in array1)
        {
            Console.Write(element);
        }
        Console.WriteLine();
    }

    static string SwapCharacters(string value, int position1, int position2)
    {
        // Swaps characters in a string.
        char[] array = value.ToCharArray();
        char temp = array[position1];
        array[position1] = array[position2];
        array[position2] = temp;
        return new string(array);
    }

    static void SwapInts(int[] array, int position1, int position2)
    {
        // Swaps elements in an array.
        int temp = array[position1];
        array[position1] = array[position2];
        array[position2] = temp;
    }
}
bac
21345

Exceptions

This code will cause exceptions if you call it with invalid parameters. If needed, you can validate the arguments with if-statements and then throw.

It is possible to develop methods that swap characters in a string or elements in an array. These methods were tested and proven correct on the input provided.