How do I display a variable?

[blueeyedlion]

Let's say that I have the integer "x", how do I display its value on the screen?

[Hiura]

Use std::stringstream to convert the variable to std::string then use sf::String (SFML 1.6) / sf::Text (2.0).

[Nexus]

In C++0x, you can also use the function std::to_string().

[blueeyedlion]

Please tell me more of this "C++0x".

[Nexus]

It is the new C++ standard, see the Wikipedia article.

[Cuban-Pete]

Something like this?

Code: [Select]


#include <sstream>
#include <string>

...
string hello;

stringstream ss (stringstream::in | stringstream::out);
ss << window.GetInput().GetMouseX();
ss << " ";
ss << window.GetInput().GetMouseY();

hello = ss.str();

sf::Text text(hello);
text.SetPosition(250.f, 450.f);
text.SetColor(sf::Color(255, 255, 255, 170));
window.Draw(text);
...


[Nexus]

Yes, but you are doing it more complicated than necessary.

Code: [Select]

std::ostringstream ss; // only output stream!
ss << window.GetInput().GetMouseX() << " " << window.GetInput().GetMouseY();

sf::Text text(ss.str());

[Cuban-Pete]

Thanks. That is a lot cleaner.

Is it wise to make a global ostringstream and use it multiple times? I guess I also need to clear it after each use.

Or would a function be better. How would I make such a function, the identifier can be int/char or whatever floats.

[Nexus]

Is it wise to make a global ostringstream and use it multiple times? I guess I also need to clear it after each use.

No. Generally, keep variables as local as possible.

Or would a function be better. How would I make such a function, the identifier can be int/char or whatever floats.

I wouldn't write a function, rather a small class with conversion operators, as shown here. But sticking to a stringstream object isn't a bad idea, either.

[Cuban-Pete]

Ahh, that works gorgeous. Small crit on your code in the other post. For me it only worked when changing str() to string().  

[Nexus]

For me it only worked when changing str() to string().

This shouldn't happen. std::stringstream clearly has a member function called str() and not string(). Do you have a macro with this name?

Or could you show a minimal code and the error message?

[Xander314]

Just a note: to 'clear' the stringstream buffer, just do this:

Code: [Select]


std::ostringstream oss;
// etc
oss.str("");


changing str() to string()

Hmmm. That seems odd. What compiler are you using?
http://cplusplus.com/reference/iostream/ostringstream/str/

[Nexus]

This works as str() returns a reference to the buffer, rather than just its value.

No, str() returns a std::string with the same content as the buffer, i.e. a copy.

str() is just an overloaded function. The overload with a parameter acts as a setter, the one without as a getter.

[Xander314]

Sorry, my mistake. How embarassing - I linked to the documentation and I hadn't even read it properly  :oops:

[Cuban-Pete]

I get this error:

error C3861: 'str': identifier not found

I have to use this also to make it work:

#include <string>
#include <iostream>
#include <sstream>
using namespace std;

Which suggests that I'm using std::string() instead of str().