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Probably a very basic question but i'm new to c++

What's the most efficient (mem) way to copy string 'a' to string 'b'? Now i
do:

char a[1000];
char* b; // length not known...could be 1000
strcpy(a, b);

Is it really necessary that 'a' always gets allocated the max size of 'b',
or can this be done more efficiently?

Thanks in advance,
Mark

"Mark van Heeswijk" <blackhawk+> wrote in message
news:diM3b.22215$.. .
> Probably a very basic question but i'm new to c++
>
> What's the most efficient (mem) way to copy string 'a' to string 'b'? Now
i
> do:
>
> char a[1000];
> char* b; // length not known...could be 1000
> strcpy(a, b);
>
> Is it really necessary that 'a' always gets allocated the max size of 'b',
> or can this be done more efficiently?
>
> Thanks in advance,
> Mark
>

The most efficient way to copy a string is to use the std::string class.

#include <string>

std::string a = whatever;
std::string b = a; // copies string a to string b

Don't mess around with char arrays, learn some proper C++ and use the C++
string class.

john

> > What's the most efficient (mem) way to copy string 'a' to string 'b'?
Now
> i
> > do:
> >
> > char a[1000];
> > char* b; // length not known...could be 1000
> > strcpy(a, b);
> >
> > Is it really necessary that 'a' always gets allocated the max size of
'b',
> > or can this be done more efficiently?
> >
> > Thanks in advance,
> > Mark
> >
>
> The most efficient way to copy a string is to use the std::string class.
>
> #include <string>
>
> std::string a = whatever;
> std::string b = a; // copies string a to string b
>
> Don't mess around with char arrays, learn some proper C++ and use the C++
> string class.


what is the std namespace used for? used for all C++ header files?

asasas

"Newsnet Customer" <> wrote in message
news:...
> > > What's the most efficient (mem) way to copy string 'a' to string 'b'?
> Now
> > i
> > > do:
> > >
> > > char a[1000];
> > > char* b; // length not known...could be 1000
> > > strcpy(a, b);
> > >
> > > Is it really necessary that 'a' always gets allocated the max size of
> 'b',
> > > or can this be done more efficiently?
> > >
> > > Thanks in advance,
> > > Mark
> > >
> >
> > The most efficient way to copy a string is to use the std::string class.
> >
> > #include <string>
> >
> > std::string a = whatever;
> > std::string b = a; // copies string a to string b
> >
> > Don't mess around with char arrays, learn some proper C++ and use the
C++
> > string class.
>
>
> what is the std namespace used for? used for all C++ header files?
>
> asasas
>

The std namespace is for the C++ standard library, which means things like
std::string, std::cout, std::vector, std::map etc. Any standard header file
without a .h is the C++ standard library.

john