Queries about strstream.h

[vishnu mahendra]

hello to all,
#include<iostre am.h>
#include<conio. h>
#include <strstream.h>
void main()
{
clrscr();
strstream str;
char *a = new char[50];
int i;
cin >> i;


ostrstream s;
s<<"\nvalue of i is "<<i<<ends;
cout<<"\nIn s we have"<<s.str();

str<<i<<ends;
cout<<"\nusing rdbuf "<<str.rdbu f();

getch();
}

correct me if i am wrong.
Is Strstream is just used for converting interger and formatting it into strings.

what is the difference between "s.str()" and "str.rdbuf( )" ?
the output is the same.

Did strstream have anyother functions.
I checked c++ library , but i cannot understand a word.


thankyou in advance,
vishnu

[Buster]

Re: Queries about strstream.h

vishnu mahendra wrote:

Your textbook is due for recycling. Please don't sell it on.
[color=blue]
> #include<iostre am.h>[/color]

Wrong. The standard C++ header you want is called 'iostream',
without the ".h".
[color=blue]
> #include<conio. h>[/color]

Wrong. There is no standard C++ header corresponding to this one.
[color=blue]
> #include <strstream.h>[/color]

Wrong. This header and everything it provides is deprecated.
You should use the 'sstream' header and the 'stringstream'
class template instead.
[color=blue]
> void main()[/color]

Wrong. The main function always returns int.
[color=blue]
> {
> clrscr();[/color]

Wrong. There is no way to clear the console's screen in standard C++.
[color=blue]
> strstream str;[/color]

Should be "std::stringstr eam str;", but why bother, if you're not going
to use it?
[color=blue]
> char *a = new char[50];[/color]

(i). You never delete [] the memory allocated here. That's bad.
(ii). You never use the variable a at all, so don't declare it.
(iii). Why 50?

Use std::string for strings.
[color=blue]
> int i;
> cin >> i;[/color]

Should be "std::cin >> i;".
[color=blue]
>
> ostrstream s;[/color]

Should be "std::ostringst ream s;"
[color=blue]
> s<<"\nvalue of i is "<<i<<ends;[/color]

You don't need the "ends" with std::stringstre am,
since std::string doesn't need to be null-terminated.
[color=blue]
> cout<<"\nIn s we have"<<s.str();[/color]

OK, but qualify "cout" with "std::".
[color=blue]
> str<<i<<ends;[/color]

What was that for?
[color=blue]
> cout<<"\nusing rdbuf "<<str.rdbu f();[/color]

I daresay you don't need to know about std::basic_ios <>::rdbuf () yet.
[color=blue]
> getch();[/color]

Wrong. There is no way to wait for a single keypress in standard C++.[color=blue]
> }
>
> correct me if i am wrong.
> Is Strstream is just used for converting interger and formatting it into strings.[/color]

You shouldn't be using it at all. stringstream, on the other hand, is
used for converting any built-in type into a string. It also works with
user-defined types if you provide the right overloaded << operator.
[color=blue]
> what is the difference between "s.str()" and "str.rdbuf( )" ?
> the output is the same.[/color]

std::stringstre am::str () returns the string you want. std::basic_ios
<>::rdbuf () returns a pointer to the streambuf used by the stream
object on which it is called. The << operator is overloaded in the
basic_ostream class to allow the insertion of a streambuf into an output
stream. This is mostly of interest to people implementing stream, not
users.
[color=blue]
> Did strstream have anyother functions.[/color]

std::stringstre am has lots of member functions.
[color=blue]
> I checked c++ library , but i cannot understand a word.[/color]

Get a better book. I recommend "The C++ Programming Language",
3rd/Special edition, by Bjarne Stroustrup, for starters.
[color=blue]
> thankyou in advance,
> vishnu[/color]

--
Regards,
Buster.

[Buster]

Re: Queries about strstream.h

vishnu mahendra wrote:

Your textbook is due for recycling. Please don't sell it on.
[color=blue]
> #include<iostre am.h>[/color]

Wrong. The standard C++ header you want is called 'iostream',
without the ".h".
[color=blue]
> #include<conio. h>[/color]

Wrong. There is no standard C++ header corresponding to this one.
[color=blue]
> #include <strstream.h>[/color]

Wrong. This header and everything it provides is deprecated.
You should use the 'sstream' header and the 'stringstream'
class template instead.
[color=blue]
> void main()[/color]

Wrong. The main function always returns int.
[color=blue]
> {
> clrscr();[/color]

Wrong. There is no way to clear the console's screen in standard C++.
[color=blue]
> strstream str;[/color]

Should be "std::stringstr eam str;", but why bother, if you're not going
to use it?
[color=blue]
> char *a = new char[50];[/color]

(i). You never delete [] the memory allocated here. That's bad.
(ii). You never use the variable a at all, so don't declare it.
(iii). Why 50?

Use std::string for strings.
[color=blue]
> int i;
> cin >> i;[/color]

Should be "std::cin >> i;".
[color=blue]
>
> ostrstream s;[/color]

Should be "std::ostringst ream s;"
[color=blue]
> s<<"\nvalue of i is "<<i<<ends;[/color]

You don't need the "ends" with std::stringstre am,
since std::string doesn't need to be null-terminated.
[color=blue]
> cout<<"\nIn s we have"<<s.str();[/color]

OK, but qualify "cout" with "std::".
[color=blue]
> str<<i<<ends;[/color]

What was that for?
[color=blue]
> cout<<"\nusing rdbuf "<<str.rdbu f();[/color]

I daresay you don't need to know about std::basic_ios <>::rdbuf () yet.
[color=blue]
> getch();[/color]

Wrong. There is no way to wait for a single keypress in standard C++.[color=blue]
> }
>
> correct me if i am wrong.
> Is Strstream is just used for converting interger and formatting it into strings.[/color]

You shouldn't be using it at all. stringstream, on the other hand, is
used for converting any built-in type into a string. It also works with
user-defined types if you provide the right overloaded << operator.
[color=blue]
> what is the difference between "s.str()" and "str.rdbuf( )" ?
> the output is the same.[/color]

std::stringstre am::str () returns the string you want. std::basic_ios
<>::rdbuf () returns a pointer to the streambuf used by the stream
object on which it is called. The << operator is overloaded in the
basic_ostream class to allow the insertion of a streambuf into an output
stream. This is mostly of interest to people implementing stream, not
users.
[color=blue]
> Did strstream have anyother functions.[/color]

std::stringstre am has lots of member functions.
[color=blue]
> I checked c++ library , but i cannot understand a word.[/color]

Get a better book. I recommend "The C++ Programming Language",
3rd/Special edition, by Bjarne Stroustrup, for starters.
[color=blue]
> thankyou in advance,
> vishnu[/color]

--
Regards,
Buster.

[vishnu mahendra]

Re: Queries about strstream.h

Hello sir,

Thank you for the help. your help is much appreciated.
By the way i forgot to tell you that i am using Turbo C++.
i am a newbie so i made lots of mistakes.

thankyou again,
vishnu

[vishnu mahendra]

Re: Queries about strstream.h

Hello sir,

Thank you for the help. your help is much appreciated.
By the way i forgot to tell you that i am using Turbo C++.
i am a newbie so i made lots of mistakes.

thankyou again,
vishnu

[Buster]

Re: Queries about strstream.h

vishnu mahendra wrote:
[color=blue]
> Thank you for the help. your help is much appreciated.
> By the way i forgot to tell you that i am using Turbo C++.
> i am a newbie so i made lots of mistakes.[/color]

I'm glad you found it helpful. Sorry if I was rude.

--
Regards,
Buster.

[Buster]

Re: Queries about strstream.h

vishnu mahendra wrote:
[color=blue]
> Thank you for the help. your help is much appreciated.
> By the way i forgot to tell you that i am using Turbo C++.
> i am a newbie so i made lots of mistakes.[/color]

I'm glad you found it helpful. Sorry if I was rude.

--
Regards,
Buster.