Reverse a String by swapping

In this example, We will learn c program to reverse a string by swapping. For this, You must have knowledge in following topics

• While Loop

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Algorithm

This is the algorithm of this program

Step 1: Start
Step 2: Initialize string str, ch and interger n = 0
Step 3: Takes string from user and store to str variable
Step 4: Repeat this step until str[i] != \\\'\\\\0\\\'
        Increase count by 1
Step 5: Assign i = 0
Step 6: Repeat this step until i < n / 2
        ch = str[i]
        str[i] = str[n - i - 1]
        str[n - i - 1] = ch
Step 8: Print str
Step 9: End

Flowchart

This is the flowchart of this program

CODE: Reverse a String by swapping

Now, We will see the code to reverse a string.

#include <stdio.h>
#include <string.h>

int main(){

  	char str[1000], ch;
	int n = 0;

	printf("Enter string to reverse : ");
	gets(str);

  	printf("\nOriginal String : %s", str);
  
  	//finding the length of the string
  	while (str[n] != '\0'){
		n++;
  	}

  	for (int i = 0; i < n / 2; i++){
    	ch = str[i];
    	str[i] = str[n - i - 1];
    	str[n - i - 1] = ch;
  	}
  
  	printf("\nString After Reverse : %s", str);
  	
	return 0;
}

The output of above program is

Enter string to reverse : Suresh

String Before Reverse: Suresh
String After Reverse: hseruS