Or and not equal

Question

Why does this work?

#include 
#include 
using namespace std;
int main(){
string s=\"a\";
if((s==\"cm\")||(s==\"in\")||(s==\"ft\")||         


        

Answer 1

(s!="cm")||(s!="in")||(s!="ft")||(s!="m")

Each and everyone of those is true, so clearly the expression is true.