String to int

[pegazaus]

Is there a way to convert a string (class string) to int in c++, Other than atoi()? I mean is there a function writen, specially for C++, that does that?

 

[TonyGroves]

None that I know of, and more's the pity. If you were using VCL/CLX, you could use AnsiString::ToInt().

 

[2ffat]

Hmmmm. I know that in BCB AnsiString does. I haven't used the STL strings in a while so I don't remember.



James P. Cottingham
-----------------------------------------
[sup]I'm number 1,229!
I'm number 1,229![/sup]

 

[TonyGroves]

There is a C++ way:
[tt]
#include <sstream>
std::string s="123";
int i;
(std::istringstream)s >> i;
[/tt]
But it's not as convenient (nor as fast, presumably) as atoi.

 

[2ffat]

I thought about the string streams and I've used them to take an int to a string. I never thought about doing it the other way around.


James P. Cottingham
-----------------------------------------
[sup]I'm number 1,229!
I'm number 1,229![/sup]

 

[Ginka]

AnsiString myString = "123";
int myInteger;

myInteger = myString.ToInt();
or
myInteger = StrToInt(myString);

I suggest you use a try catch clause to prevent a failure.

 

[rickwookie]

or use:

myInteger = myString.ToIntDef(-1);
or
myInteger = StrToIntDef(myString, -1);

to supply a default value (in this case -1) in the case of an invalid string.

 

[chipperMDW]

Boost's (

http://www.boost.org)

[tt]lexical_cast[/tt] function template takes the stringstream technique and encapsulates it into an easy-to-use package that works as you'd expect for anything that has sensible << and >> operators.