C function to swap strings

The following is an example of swapping strings.

Example

#include <stdio.h>
#include <string.h>
int main() {
　　　char st1[] = "My　1st string";
　　　char st2[] = "My　2nd string";
　　　char swap;
　　　int i = 0;
　　　while(st1[i] != '\0') {
　　　　　　swap = st1[i];
　　　　　　st1[i] = st2[i];
　　　　　　st2[i] = swap;
　　　　　　i++;
　　　}
　　　printf("After swapping s1　: %s\n", st1);
　　　printf("After swapping s2　: %s\n", st2);
　　　return 0;
}

output result

After swapping s1　: My　2nd string
After swapping s2　: My　1st string

In the above program, two char types are declared as st1and st2array, a char variable 'swap', and an integer variable i. In the loop to check st1is not null, swap st1and st2value.

char st1[] = "My　1st string";
char st2[] = "My　2nd string";
char swap;
int i = 0;
while(st1[i] != '\0') {
　　　swap = st1[i];
　　　st1[i] = st2[i];
　　　st2[i] = swap;
　　　i++;
}