C Program to Reverse a String using Pointer

Below is a program to reverse a string using pointer:

#include <stdio.h>
int main()
{
 printf("\n\n\t\tStudytonight - Best place to learn\n\n\n");
 char str[100];
 char rev[100];
 char *sptr = str; // sptr stores the base address of the str
 char *rptr = rev; // rptr stores the base address of the reverse
 int i = -1;
 printf("\n\nEnter a string: ");
 scanf("%s", str);
 // storing the ending address of str in sptr
 while(*sptr)
 {
 sptr++;
 i++; // i is the index of the end location
 }
 // storing the string str in rev in reverse order
 while(i >= 0)
 {
 /*
 First decrementing then using as it stores 
 the location after the end location due to above while loop
 */
 sptr--; 
 *rptr = *sptr; // storing the value in sptr in rptr
 rptr++; // pointing to next location
 i--; // decrementing the index
 }
 /*
 String should always end with '0円' so explicitly 
 putting it at the end of the string
 */
 *rptr = '0円'; 
 rptr = rev; // restoring the base address of the reverse string
 // storing the reverse string in the original string
 while(*rptr)
 {
 *sptr = *rptr;
 sptr++;
 rptr++;
 }
 // printing the reverse string
 printf("\n\nReverse of the string is: %s ", str);
 printf("\n\n\t\t\tCoding is Fun !\n\n\n");
 return 0;
}

Output:

Reversing a String using Pointer