Question

this code

#include <iostream>

using namespace std;
int main(){
  bool t=false;
  cout<<t &&(!t)<<endl;

  return 0;
}

shows me error like this

invalid operands of types ‘bool’ and ” to binary
‘operator<<‘

What is wrong? I can’t understand this, please explain it to me. I think that && and ! is defined in c++.

So what is wrong?

Answer 1

“invalid operands of types ‘bool’ and ” to binary ‘operator<<‘”

This means that the second << operator is trying to execute on (!t) and ‘endl’.

<< has a higher precedence than && so your cout statement executes like this:

(cout << t ) && ( (!t) << endl );

Add parenthesis to fix this:

cout << (t && (!t) ) << endl ;

Look here for order of operations when statements are not evaluating as expected.