need help with string

[justin1232]

I have three variables:

const char* dir //directory of file

int i //the file's name without extension

const char* ext //the extension of the file

how do I add these together to get a const char* string that should look like this:

"img/1.bmp"

Thanks,



~justin123

[GCDEF]

sprintf would be one way.

[justin1232]

would this work:

sprintf(name,"%d",dir+i+ext);

[Russco]

are you using C or C++??

In C++ you would use std::string and stringstreams.

In C you would use char* and sprintf. sprintf is pretty similar to printf except it prints to an area in memory and not the screen. If that sprintf were a printf, do you think it would print on the screen what you want?

[GCDEF]

would this work:

sprintf(name,"%d",dir+i+ext);

No.

[justin1232]

im using c++ and i have no clue on how to do this.

[Joeman]

the c++ way

#include <string>
#include <sstream>
 
template< class Type >
std::string ToString( Type Input )
{
    std::stringstream Out;
    Out << Input;
    return Out.str();
}
 
using namespace std;
string File = ToString( Dir ) + ToString( I ) + ToString( Ext );

[justin1232]

that part works, but how do i convert "file" to a const char* string so the function thats using it can understand it?

[Joeman]

File.c_str();

http://www.cplusplus.com/reference/string/string/

is this function yours? if so, you should change it to

void Input( const string& File );