Boolean function problems

Question

Having trouble with my boolean function. When I compile the program everything runs just fine, yet when I type in "no" it still says "what can I help you with?".

#include <iostream>
#include <string> //size()
#include <cctype> //isdigit()
using namespace std; //(xxx)xxx-xxxx

bool verification(string yesOrno)
{
    if(yesOrno == "yes")return(true);
    else               return(false);
}

int main()
{
    string yesOrno;

    cout <<"Do you need more help\n";
    cin >> yesOrno;

    if(!verification(yesOrno))cout <<"What can I help you with?\n";

    return(0);
}

On a side note, you can make the verification evaluation a lot simpler by using return (yesOrno == "yes"); instead of adding in the extra step and complicating things unnecessarily. — Bryn McKerracher
– Bryn McKerracher, Commented Jul 18, 2015 at 4:20
@MattMcNabb I read that as meaning "comment 2 and 4 (to this question) are cryptic", and ... spent a good minute just appreciating such a meta-observation. — Drew Dormann
– Drew Dormann, Commented Jul 18, 2015 at 5:56

Mureinik · Accepted Answer · 2015-07-18 04:04:43Z

3

Your logic is backwards - verification returns false for anything that isn't "yes". Since "no" isn't "yes", verification("no") returns false, and in the main function you print out this message if !verification("no"), which evaluates to true.

Seems like you should drop the ! operator from the if statement.

answered Jul 18, 2015 at 4:04

Mureinik

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Comments

deadPix3l · Accepted Answer · 2015-07-18 04:09:22Z

1

What happens when you type yes? Whats happening is when you type no, it returns false. Which you then reverse (!) to true. It works fine but youre flipping it, so instead of only working on "yes", it actually works on everything but " yes".

Remove the ! (Not operator) and it will work as you expect.

answered Jul 18, 2015 at 4:09

deadPix3l

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