I wrote a code to reverse a string using recursion. When I run it, I get a segmentation error.
#include <stdio.h>
void _print_rev_recursion(char *s);
int main() {
_print_rev_recursion("string reversal");
return (0);
}
void _print_rev_recursion(char *s)
{
if (!*s)
return;
_print_rev_recursion(s++);
putchar(*s);
}
When I changed s++ to s + 1, the code works.
I thought both s++ and s+1 mean the same thing. I need clarification please.
This is the code that works:
#include <stdio.h>
void _print_rev_recursion(char *s);
int main() {
_print_rev_recursion("string reversal");
return (0);
}
void _print_rev_recursion(char *s)
{
if (!*s)
return;
_print_rev_recursion(s + 1);
putchar(*s);
}
>Solution :
ptr++ is a postfix increment operator, while ptr + 1 is an arithmetic expression that adds 1 to the value of ptr.
The main difference between the two is that ptr++ increments the value of ptr by 1 after the current statement has been executed, while ptr + 1 adds 1 to the current value of ptr but does not change the value of ptr itself.
For example, consider the following code:
int i = 1;
int j = i++;
After this code has been executed, the value of i will be 2, but the value of j will be 1, because the postfix increment operator increments the value of i after it has been assigned to j.
On the other hand, consider the following code:
int i = 1;
int j = i + 1;
After this code has been executed, the value of i will still be 1, but the value of j will be 2, because the arithmetic expression i + 1 adds 1 to the current value of i but does not change the value of i itself.