Thread: strings in c++

There are a lot of tutorials if you google.

To give you the code with strings to convince you that strings are easier in C++:

Code:

using namespace std;
void func1(char *str);

int main ()
{
      string str;
   
      str = "Hello friend";
      func1(string);

      cout << str;

      return 0;
}

void func1(string& str)
{
     for(i=0; i<str.size(); ++i)
     {
          if (isupper(str[i]))
          str[i] = tolower(str[i]);

         else if (islower(str[i])
         str[i] = toupper(str[i]);
      }
}

Just keep these in mind:
1) You don't have to give a size. Everything is done automatically for you
2) You can use = to copy, don't need strcpy(). You can use + combine strings
3) A lot useful functions http://www.cppreference.com/wiki/string/start

EDIT: (hope nobody realized what I edited )

It appears that the getchar() is accepting the ENTER from a previous user input within the main. Thus I have just slipped an fflush(stdin); in before the getchar() is called.

fflush(stdin) is undefined as fflush() works on output streams. Use one of the methods for "flushing" the input stream as described in the FAQ.

Try this FAQ: How do I... Flush the input buffer.

Actually, there's a possibly better solution:

Code:

std::cin.ignore(std::numeric_limits<std::streamsize>::max(), '\n');
std::cin.get(); // for the "pausing" effect that you want

You should #include <limits> to std::numeric_limits.

Originally Posted by C_ntua

Code:

using namespace std;
void func1(char *str);

EDIT: (hope nobody realized what I edited )

One more thing to edit... You forgot to change the prototype to string& also.

Though it's likely a little bit advanced for you, just to show you a tiny bit of what's possible down the road if you continue to explore the language here's an example of one possible solution to your code that demonstrates the use of what is known as a function object and a helper function called transform (in the <algorithm> header)... just to give you an idea of the myriad different ways that this can be done.

Code:

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

struct flipcase
{
    inline char operator()(char in) const
    {
        if(islower(in)) return toupper(in);
        else return tolower(in);
    }
};

int main()
{
    std::string str("Hello My Friend");

    std::cout << "Before: " << str << std::endl;

    std::transform(str.begin(),str.end(),str.begin(),flipcase());

    std::cout << "After : " << str << std::endl;

    return 0;
}

Output should be:

Code:

Before: Hello My Friend
After : hELLO mY fRIEND