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

Negation changes the logic behind it. There's more theory here http://en.wikipedia.org/wiki/Negation but basically, in the second example, you want to check that none of the conditions match - meaning you'd have to have && (and) operator instead of || (or)