C++ classes getting value using pointers and strcpy

Question

I am trying to understand C++. Can anybody explain what this code does exactly, I understood that it is some type of setter and getter in Java but I am not sure.

Comm::Comm(const char* id)
{
strcpy(this->id, id);
}


char* Comm::getId()
{
   return id;
}

I strongly recommend for you to get some book that will teach your C++ grounds up. I must say that "Beginning C++ through game programming" is not half bad. — Tymoteusz Paul, Jan 05 '14 at 21:09
This question appears to be off-topic because it would be better suited to a chatroom, or a discussion forum, or a one-on-one mentoring session. — Lightness Races in Orbit, Jan 05 '14 at 21:30
It unsafely copies a null-terminated string to what I can only assume is an array of characters in the class `Comm`. Since there is no bounds checking / truncation, this is terrible. `strncpy (...)` would make me cringe a lot less. — Andon M. Coleman, Jan 05 '14 at 22:08

score 7 · Answer 1 · edited May 23 '17 at 11:56

7

What does this code do?

It burns the eyes of children.

The assumption here is that the class Comm has a member variable of type char* or char[N]. There is no "setter" per se, but Comm's constructor attempts to copy its input to that member variable. The getId function is a getter for this member variable.

Depending on the rest of the code, this could be totally flawed due to lack of memory allocation, lack of memory de-allocation, and lack of copy semantics. At best the member is an array and then the lack of range checking in the strcpy call is a serious security risk.

The class would be much better redesigned with the use of std::string.

I would not encourage you to learn from this code snippet.

Instead, learn from a good book.

edited May 23 '17 at 11:56

Community

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answered Jan 05 '14 at 21:09

Lightness Races in Orbit

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This answer is useless, too – Jan 05 '14 at 21:14
@DieterLücking: Thanks for your mature and productive contribution. – Lightness Races in Orbit Jan 05 '14 at 21:15
1

Thanks for your well informed 'It burns the eyes of children' – Jan 05 '14 at 21:18
@DieterLücking: You know, I _did_ write other words... – Lightness Races in Orbit Jan 05 '14 at 21:19
How helpful is 'I would not encourage you to learn from this code snippet' ? – Jan 05 '14 at 21:20
4

@DieterLücking: How is it _not_ helpful? The OP may not be aware that this is potentially very poor code. How does telling him about this not help? I am sharing my expertise for free. That is helpful. Your whining on my answer without giving any constructive criticism _whatsoever_ is _not_ helpful. Please cease, and feel free to write your own answer if you think you can do so much better! – Lightness Races in Orbit Jan 05 '14 at 21:21

C++ classes getting value using pointers and strcpy

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