String to Int How?

[JasonLpz]

is this the proper way?

5. How to convert a string to a number?

- Use the atoi function to convert a string to an integer.

Example:

---------------------------------------------------------------------------------------------------------------------------

#include <iostream> //preprocessor statement

#include <stdlib.h> //contains itoa & atoi

using namespace std; //choosing the namespace that we are going to use



int main() //this is where the program starts executing

{

char buffer[20];

int i = 3445;

_itoa( i, buffer, 10 );

cout<<buffer<<endl;

return 0;

}

Is that the way its the same as he has for the Int to String. I found this in the main tutorial link
I Tried using the below

char buffer[20]; 
                          char buffer2[20]; 
                          
                          ::GetWindowText (edit,buffer,255);
                          ::GetWindowText (edit,buffer2,255);
            
                          int i = buffer;
                          int i2 = buffer2;
                          int i3 = i + i2;    
 
                        _itoa( i, buffer, 10 );
                        _itoa( i2, buffer2, 10 );

[CornedBee]

char buffer2[20]; 

::GetWindowText (edit,buffer,255);
::GetWindowText (edit,buffer2,255);
int i = buffer;
int i2 = buffer2;
int i3 = i + i2;	  

_itoa( i, buffer, 10 );
_itoa( i2, buffer2, 10 );

Ok, think about it. First, you allocate a buffer for 19 characters. Then you retrieve the text of an edit box, where you tell windows that you have space for 255 characters. First error.
Then you assign the buffers to integers. This won't compile. And in the thing you quoted it says "Use the atoi function to convert a string to an integer." Second error.
Finally you convert those integers (that have a random value) back to strings and store them in the buffers. I guess that's not what you wanted to do either.

Ok, so you basically used the wrong function. Here's how to get an integer from an edit box:

char buffer[256]; // You gotta keep your promises.
::GetWindowText(edit, buffer, 255);
int i = atoi(buffer);

Or simpler (if you have the id of the edit box):

int i = ::GetDlgItemInt(IDC_EDIT);

_itoa is a Microsoft-specific function. The standard way to convert an integer to a string in C is sprintf:

sprintf(buffer, "%i", i);

and in C++ stringstream

std::ostringstream oss;
oss << i;
std::string s = oss.str();

(from the header <sstream>).

[JasonLpz]

ok so far so good now i tried

std:stringstream oss;
oss << i3;
std::string s = oss.str();

but no good i get like 3 errors
DO i have to include any h files?

[JasonLpz]

Ok now i got it lol im so stupid thanks alot you do help so much and srry bout before

char buffer[256]; // You gotta keep your promises.
char buffer2[256]; // You gotta keep your promises.
char buffer3[256]; // You gotta keep your promises.
 
::GetWindowText(edit, buffer, 255);
::GetWindowText(edit2, buffer2, 255);
 
     int i = atoi(buffer);             
     int i2 = atoi(buffer2);
     int i3 = i + i2;
                
sprintf(buffer3, "%i", i3);
::SetWindowText(edit3,buffer3);

[McCain]

(from the header <sstream> ).

DO i have to include any h files?

I rest my case...

[CornedBee]

And <string> too.