the right most 10 characters of a string

Hi gurus:

What is a function that will return the rightmost 10 or n characteres of a string? Like the VB right$ function?

THanks,

Luis

string Str("1234567890123");
int n = 10;

cout << Str.substr( Str.size() - n , n).c_str();

Quote:

---

Originally posted by Guysl
string Str("1234567890123");
int n = 10;

cout << Str.substr( Str.size() - n , n).c_str();

---

I think there is no need for any conversion
just std::cout<<str.substr(fromhere, tothere);
it is still safe, no harm at all...

Quote:

---

I think there is no need for any conversion
just std::cout<<str.substr(fromhere, tothere);
it is still safe, no harm at all...

---

1. what "conversion"?
if you are referering 'int n', then its just an example for
a variable use as a parameter.

2. the original request was rightmost characters, so
fromwhere=? tothere=?

3. second parameter of substr is the length, not the end position.

4. (-- deleted -- )

You don't have to call c_str(), since the streams have overloaded operators for std::string. But yeah, it does return the rightmost n characters.

weird, how come VC++ 6 doesn't let me streaming the string without c_str(). are there any compiler switches I have to change?

btw, program is crashing while n>size(), so a correction:
cout << Str.substr( n>Str.size() ? 0 : Str.size() - n , n);

Quote:

---

Originally posted by Guysl
3. second parameter of substr is the length, not the end position.

---

okay, okay, i didnt say anything, why did you get trembling so soon ?
Fine, I just meant a mask is just for the face not for the whole body, mate !
Look at the way Vyes answered, sure you are gonna be VIP..:) Hello.
No matter who you acutally are, to me you are Guysl, now its my turn to make it right again, sorry for being a stickie pickie.

What is length here ? up there I meant your #3. Okay , please Guysl let me say this is not a correct because it is the end position not the length..

Oh it is really weird why even a newb C++ can also write this thing. I hope there is nothing in there...
Dont worry, it is just an temporarely annoying problem of C++....Later people can learn more about it...

Regards,

-Fiona

PS: You can call me Niner, that is what Robert Lovelace used to call me...:) I am glad to meet you...

Quote:

---

Originally posted by Guysl
btw, program is crashing while n>size(), so a correction:
cout << Str.substr( n>Str.size() ? 0 : Str.size() - n , n);

---

Great !

LittleShay,
frankly, I didn't understand your last post (except of the smilies ;) )
please accept my apology if I hurt you in some way.

anyway, substr second parameter is not a position but
the number of characters (length):

http://msdn.microsoft.com/library/de...ringsubstr.asp

Regards,
Guy

Thanks for all the answers. Now, I don´t mean to complicate things but, if I do:

char result[10];

string Str("Hello Gurus, good day!");
int n = 10;

and then;

strcpy(result,Str.substr( Str.size() - n , n).c_str());

Will that add the '\0' at the end of the string?

'cause the idea es to copy a substring to a string. You see, I have a dipslay field (on a console program) that is only 10, and when I try to display the results of a certain event, it overflows the field and overwrites it's neighbors.

Thanks!

Luis

strcpy copies from source until it get a '\0', and it copies it as well.

Quote:

---

Originally posted by taguato
char result[10];
string Str("Hello Gurus, good day!");
int n = 10;
strcpy(result,Str.substr( Str.size() - n , n).c_str());

Will that add the '\0' at the end of the string?

---

The c_str() call will add a \0 to the string, i.e. make it a C-String. strcpy will copy everything up to and including the \0 character.

In other words, your example above will crash, as you need 11 bytes to store 10 characters plus a \0 and result only reserves 10.

Quote:

---

Originally posted by Guysl
weird, how come VC++ 6 doesn't let me streaming the string without c_str(). are there any compiler switches I have to change?

---

Code:

---

#include <iostream>
#include <string>
int main()
{
    std::string myString = "Hello World!";
    std::cout << myString << std::endl;
}

---

Make sure you are using the correct iostream header, and make sure you include <string>. Getting either of those wrong will give you an error in VC++ 6.0.

Thanks.
I'm using the same headers but keep getting:
error C2679: binary '<<' : no operator defined....

I have the DX9 SDK installed too, with default project setting
uses its libs, could it be the reason? any idea?

Regards,
Guysl