Why s1=!s2 ??

Question

#include<stdio.h>
int main() {

typedef struct { char ch; } st;
st s1 = {'c'};
st s2 = s1;
if(s1 == s2)
printf("Successful");
return 0;

// output
Compile error

Answer 1

You cannot compare the struct, that is you can't apply the following:
==, !=, <, <=, >, >=.

The best you can do is compare the member. In your case it could be if(s1.ch == s2. ch).

Answer 2

You are not supposed to compare the structs. You have to compare the values. So it should be:

s1.ch == s2.ch

Answer 3

Infinity CarrieForle yes now I got it. Thanks.