Reverse a string in C

               Reverse a string deal with reverse each character of the entire string. It can be done by user defined function or built-in function.

First, we implement it using the user defined function.

It uses reverse_String() for implementing the function.

👉C Code:

//include the header files

#include <stdio.h>

#include <string.h>

//a user defined function ‘reverse_String()’ is defined here.

//starting and ending point and temporary variables are created.

//each character is read and reversed using temp variable.

void reverse_String(char s[]) {

    int start = 0;

    int end = strlen(s) - 1;

    char temp;

    while (start < end) {

        // Exchange the characters

        temp = s[start];

        s[start] = s[end];

        s[end] = temp;

        start++;

        end--;

    }

}

//It creates a character array.

//Get the string from the user

//call the reverse_String() function to reverse the string

//print the reversed String

int main() {

    char s[100];

    printf("Enter a string: ");

    scanf("%s", s);

    reverse_String(s);

    printf("Reversed string: %s\n", s);

    return 0;

}

𜰘Output:

Enter a string: startItnow

Reversed string: wontItrats

User defined string reverse function is successful.

Next one is built-in functions implementation.

This code uses strlen() built-in function.

𛲣Steps:

• Two char arrays are declared with 100 size. Two integer variables are declared.
• Read the input from the user.
• Find the string length using strlen().
• Reverse the string using a for loop.
• Finally, print the output.

👉Code:

//The header file inclusion

#include <string.h>

#include<stdio.h>

// main() function

    char s[100], rev_s[100];

    int i, s_len;

    printf("Enter the string: ");

    scanf("%s", s);

    s_len = strlen(s);  

    for (i = 0; i < s_len; i++) {

        rev_s[i] = s[s_len - i - 1]; 

    }

    rev_s[s_len] = '\0'; 

    printf("The Reversed string is: %s\n", rev_s);

    return 0;

}

✌Output:

Enter the string: Hiworld

The Reversed string is: dlrowiH

These are the two methods to implement String reverse in C. Hope; these code segments are useful for you. Keep coding!!!