Programming Forums > Application Development > C++

ike0000 · Apr 16th, 2005, 3:39 PM

Can anyone tell me how to go about copying a const char * to a char * without using anything from string or cstring (strlen, strcpy, etc.)?
For example, how can I copy const char * name to char * newname without doing something like:
newname = new char [strlen (name) + 1];
strcpy (newname, name); ?

Eggbert · Apr 16th, 2005, 3:54 PM

strcpy is a trivial function to write.

(Toggle Plain Text)

char *my_strcpy ( char *dst, const char *src )
{
  char *p = dst;

  while ( ( *p++ = *src++ ) != '\0' )
    ;

  return dst;
}

pal · Apr 17th, 2005, 10:39 PM

const char is "const", which means constant variables can not be changed.
If there is a way, please let me know as well, k.

Eggbert · Apr 18th, 2005, 12:57 PM

>const char is "const", which means constant variables can not be changed.
Correct.

>If there is a way, please let me know as well, k.
A way to do what? There are no unanswered questions on this thread.

BaroN NighT · Apr 18th, 2005, 1:31 PM

Quote:

Originally Posted by Eggbert

>If there is a way, please let me know as well, k.
A way to do what? There are no unanswered questions on this thread.

A way that you can copy char to another char without using strcpy I guess. strcpy is an ease of use function. Why would you like to find a different way?

Eggbert · Apr 18th, 2005, 7:07 PM

>A way that you can copy char to another char without using strcpy I guess.
Then the function I gave should be answer enough.

>Why would you like to find a different way?
Anyone can use library functions, but good programmers also know how they work under the hood. The only way to truly learn how they work is to implement them.

bl00dninja · Apr 20th, 2005, 2:30 AM

eggbert rules!!!

Apr 16th, 2005, 3:39 PM	#1
ike0000 Newbie Join Date: Apr 2005 Posts: 1 Rep Power: 0	*C++ programming question** Can anyone tell me how to go about copying a const char * to a char * without using anything from string or cstring (strlen, strcpy, etc.)? For example, how can I copy const char * name to char * newname without doing something like: newname = new char [strlen (name) + 1]; strcpy (newname, name); ?

Apr 16th, 2005, 3:54 PM	#2
Eggbert Professional Programmer Join Date: Nov 2004 Posts: 250 Rep Power: 4	strcpy is a trivial function to write. (Toggle Plain Text) char my_strcpy ( char dst, const char src ) { char p = dst; while ( ( p++ = src++ ) != '\0' ) ; return dst; } char my_strcpy ( char dst, const char src ) { char p = dst; while ( ( p++ = src++ ) != '\0' ) ; return dst; }

Apr 20th, 2005, 2:30 AM	#7
bl00dninja Programming Guru Join Date: Oct 2004 Location: namespace std Posts: 1,246 Rep Power: 5	eggbert rules!!! __________________ i put on my robe and wizard hat... Have you ever heard of Plato, Aristotle, Socrates?...Morons.

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Apr 17th, 2005, 10:39 PM	#3
pal Programmer Join Date: Mar 2005 Location: Washington Posts: 90 Rep Power: 4	const char is "const", which means constant variables can not be changed. If there is a way, please let me know as well, k.

Apr 18th, 2005, 12:57 PM	#4
Eggbert Professional Programmer Join Date: Nov 2004 Posts: 250 Rep Power: 4	>const char is "const", which means constant variables can not be changed. Correct. >If there is a way, please let me know as well, k. A way to do what? There are no unanswered questions on this thread.

Apr 18th, 2005, 7:07 PM	#6
Eggbert Professional Programmer Join Date: Nov 2004 Posts: 250 Rep Power: 4	>A way that you can copy char to another char without using strcpy I guess. Then the function I gave should be answer enough. >Why would you like to find a different way? Anyone can use library functions, but good programmers also know how they work under the hood. The only way to truly learn how they work is to implement them.

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Programming Forums > Application Development > C++

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