C program to reverse the given string using a pointer

In this article we will learn to implement a C program to reverse the given string using a pointer. A C program is provided below for reversing a given string using a pointer.

Program is as follows:

/*
 * C program to reverse a given string using pointers
 * Author: P.S.SuryaTeja
*/
#include <stdio.h>
#include <conio.h>
#include <math.h>
#include <stdlib.h>
#include <string.h>

void reverse(char *str)
{
	char *first, *last, temp;;
	int i, stringlength;
	first = str;
	stringlength = strlen(str);
	for(i = 0; i < stringlength - 1; i++)
		str++;
	last = str;
	str = first;
	while(first < last)
	{
		temp = *first;
		*first = *last;
		*last = temp;
		first++;
		last--;
	}
	puts(str);
}

int main(int argc, char **argv)
{
	char str[20];
	printf("Enter a string: ");
	gets(str);
	printf("Reverse of the string is: ");
	reverse(str);
    getch();
    return 0;
}

Input and output for the above program is as follows:

Enter a string: howdy
Reverse of the string is: ydwoh

Suryateja Pericherla

Suryateja Pericherla, at present is a Research Scholar (full-time Ph.D.) in the Dept. of Computer Science & Systems Engineering at Andhra University, Visakhapatnam. Previously worked as an Associate Professor in the Dept. of CSE at Vishnu Institute of Technology, India.

He has 11+ years of teaching experience and is an individual researcher whose research interests are Cloud Computing, Internet of Things, Computer Security, Network Security and Blockchain.

He is a member of professional societies like IEEE, ACM, CSI and ISCA. He published several research papers which are indexed by SCIE, WoS, Scopus, Springer and others.