Write a C Program to Reverse String using Recursion

Recursion : :

• Recursion is the process of repeating items in a self-similar way. In programming languages, if a program allows you to call a function inside the same function, then it is called a recursive call of the function.

• The C programming language supports recursion, i.e., a function to call itself. But while using recursion, programmers need to be careful to define an exit condition from the function, otherwise it will go into an infinite loop.

• Recursive functions are very useful to solve many mathematical problems, such as calculating the factorial of a number, generating Fibonacci series, etc.

Problem : :

This C Program uses recursive function & reverses the string entered by user in the same memory location.

Example : :  “codezclub” will be reversed to “bulczedoc”

Below is the source code for C Program to Reverse String using Recursion which is successfully compiled and run on Windows System to produce desired output as shown below :

SOURCE CODE : :

/* C Program to Reverse String using Recursion */


#include <stdio.h>
#include <string.h>
 
void reverse(char [], int, int);
int main()
{
    char str1[20];
    int size;
 
    printf("Enter a string to reverse: ");
    scanf("%s", str1);
    size = strlen(str1);
    reverse(str1, 0, size - 1);
    printf("The string after reversing is: %s\n", str1);
    return 0;
}
 
void reverse(char str1[], int index, int size)
{
    char temp;
    temp = str1[index];
    str1[index] = str1[size - index];
    str1[size - index] = temp;
    if (index == size / 2)
    {
        return;
    }
    reverse(str1, index + 1, size);
}

Output : :

***************** OUTPUT ********************


***************** FIRST RUN *****************

Enter a string to reverse: CodezClub
The string after reversing is: bulCzedoC



***************** SECOND RUN *****************

Enter a string to reverse: reverse
The string after reversing is: esrever