Please help with a c++ string

Thanks for your help guys. Got it all figured out.

Originally Posted by King Mir

If your using stl functions, you may as well use count:

Code:

mycount = count (message.begin(), message.end(), letter);

But jeffcobb's first example is what the book was describing.

I know how to cope with the problem that the first floor has asked, but you give me another method to handle it. So, I must show my thanks.

Originally Posted by King Mir

If your using stl functions, you may as well use count:

Code:

mycount = count (message.begin(), message.end(), letter);

But jeffcobb's first example is what the book was describing.

But this code seems to be wrong so that I can't compile it.Why?

Originally Posted by Dawnson

But this code seems to be wrong so that I can't compile it.Why?

Dunno, it works for me:

Code:

#include <string>
#include <algorithm>
#include <iostream>

int main()
{
    using namespace std;

    string message("Dawnson");
    char letter = 'n';
    string::size_type mycount = count(message.begin(), message.end(), letter);
    cout << mycount << endl;
}

The type of mycount should be the string::difference_type, not string::size_type apparently.

Originally Posted by King Mir

The type of mycount should be the string::difference_type, not string::size_type apparently.

Ah. Luckily, the result of std::count will be non-negative, the conversion from signed to unsigned is well defined, and if it is possible for the count to be greater than the maximum value of size_type, then we're probably doomed anyway since size() might return an incorrect value