Question

I am having some troubles with my if loop.

First off I have I assigned char sign.

 void evaluate_ps(istream& input) 
 {
    char sign;
    input >> sign;
    cout << sign << endl;
    check(sign);
 }

That prints / so my sign has the value ‘/’

Then I go to my void check(char operation) function

 void check(char operation)
 {
    if(operation != '-' || operation != '+' ||
      operation != '*' || operation != '/')
       {
       return false;
       }
       else return true;
 }

and it’s returning false… WHY!!!! I can’t seem to figure this out.

Thanks everyone.

Answer 1

You probably meant all your || to be &&:

if(operation != '-' && operation != '+' && 
  operation != '*' && operation != '/')

Otherwise, it will always enter the if-statement since a character will always not equal one of 4 different things.