Thread: Comparing strings - beginner question

So I've just started out programming more or less and have run into trouble. I'm going through the c++ tutorial on the site and so far doing pretty well I believe. I've tried searching about the web for a reason for the problem stated below, but have come up empty handed - mainly I suspect because of an inability to phrase my question right as my programming vocabulary I still sadly lacking.

I'll work around the problem for now, but this is the first thing I just plain don't understand - and I'd like to. Any help is greatly appreciated.

Why does this work;

Code:

#include <iostream>
#include <cstring>


using namespace std;


int main()
{
    char a[2], c[2], b[2], asdf = 'A';


    if (strcmp (a, c) + strcmp (a, c) == 2) {
        cout << "They're all the same.";
        cin.get();


    }


    else {
        cout << "They're not the same. Silly C++ - they actually are.";
        cin.get();
    }


}

While this returns error "array must be initialised with brace-enclosed initializor"?

Code:

#include <iostream>
#include <cstring>


using namespace std;


int main()
{
    char a[2], c[2], b[2] = 'A';


    if (strcmp (a, c) + strcmp (a, c) == 2) {
        cout << "They're all the same.";
        cin.get();


    }


    else {
        cout << "They're not the same. Silly C++ - they actually are.";
        cin.get();
    }


}

Note all I've done is remove the not-used asdf variable. I really don't get this, but I'll work around it in the cmd Tic Tac Toe program I'm trying to create.


Thanks a lot for your time - I hope I'm not unknowingly breaking any forum rules, but if I am I'd like help in keeping with them as well. The site so far has been by far the best resource for learning for me a complete beginner. Thanks!


EDIT; The above is just a test-program for me to try out theories and principles in. It's not part of the actual program I'm trying to create - merely me trying to understand a concept.

So I think I got around the problem with the code below which should allow me to compare the three. It seems to work. Basing my 'real' program on this. It's correct, no?

Code:

#include <iostream>
#include <cstring>


using namespace std;


int main()
{
    char a[2] = {"A"};
    char c[2] = {"A"};
    char b[2] = {"A"};


//Display variables defined above just to be certain what they are.
    cout << a << b << c << endl;
//Again for clarification to myself displaying result of equation used below. 
    cout << (a[0] == b[0]) << endl;


    if (a[0] == b[0] && a[0] == c[0]) {
        cout << "They're all the same.";
        cin.get();


    }


    else {
        cout << "They're not the same. Silly C++ - they actually are.";
        cin.get();
    }


}

Originally Posted by laserlight

This:

Code:

char a[2] = {"A"};
char c[2] = {"A"};
char b[2] = {"A"};

should be:

Code:

char a[2] = "A";
char c[2] = "A";
char b[2] = "A";

I tried it and it works too. But what's the difference? When should I use the curly brackets? EDIT; When writing to an array?


Also - should I upload the code for the finalized Tic Tac Toe for anyone interested in what I'm using this for?