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[Data]

Originally Posted by Japofran

As a matter of fact using an overloaded assignment operator with a string is not a C-ism at all... Actually the robust C code to clear a string or check if it's not empty is very brief and immediately recognizable:

*templine = '\0';

while ( *templine != '\0' );

(Actually I could write just 0 instead of '\0', couldn't I? Hm better safe than sorry.) Of course templine would here be a C string (pointer to char), not a string object. I can't do this stuff with objects and I'm not supposed to, their innards are "private".

You are totally right about the fact that using the overloaded operators is very C++ like and not C like, however for a starting programmer (for those I posted this very simple piece of code), it can be confusing and might lead to bad practices with other objects.
Maybe i should use string.append instead of the += as well.... but it doesn't make the code look more beautiful in my opinion. In my code not intended for newbies you will find lot's of classes in which I overloaded the operators in order to keep their usage intuitive. (So you don't need to learn an interface before you can use it)


You could use 0 instead of '\0' I always use 0., but this comes mainly from the fact that
in C++ NULL and 0 are the same, so I can stick with one type of 0 for everything.

I could ramble on about objects and stuff and as well, but that has fairly little to do with the solved problem.

Thank you for your discussion so far. I really appreciate it.

[Playbahnosh]

I gotta get a C book... I feel left out...

[Data]

sorry play.

[Japo]

Originally Posted by Playbahnosh

I gotta get a C book... I feel left out...

Sorry. I guess there's no point in splitting this topic in two now that one of them would be solved... :P

There are dozens of free tutorials, even whole books (tutorials are better to start).

This kind of code isn't difficult so you should get the hang of it after a while. The only special thing here is that instead of taking the trouble to call specific functions to handle files, Data took advantage of the fact that C/C++ handles files and input/output devices in the same way, as "streams". However once opened files would have been interfaced with the same kind of code. The "<" in the command line call told the OS to use one file as standard input stream, instead of the keyboard by default, and the ">" to use another file as standard output stream, instead of the console. So if you for example used the former but not the latter, you should get the intended result, but printed on the screen instead of saved to a file.

Other than that, this code is a good example for beginners wanting to start to learn input/output.

BTW Data, there was another reason to use string.empty() and .clear() instead of == and =, the same reason why they exist at all, since you've shown that you wouldn't need the former if you used the latter instead. Not that the code would be more robust, but that it would be more efficient. I know that's not an issue here, but it's good not to let that get out of sight as a good practice, so that it will come naturally when it be important. I haven't looked inside the string object source code, but I'd bet the implementations of .empty() and .clear() are similar to what I typed, and will likely be inline functions; whereas the overloaded == and = will call functions devised to operate with whole strings so they will include a loop (even when it doesn't iterate more than once).

[Data]

Japofran,
Yes you are right. empty and clear operations are most likely to be more efficient.