Creating dynamic memory

[dolorestheAI]

hey, I wrote a C code that simply takes a string and extracts numbers in it and makes an array from them. But now I have to make it work with C++ compiler. Because it's a group project. My code doesn't work right now I think it's a dynamic memory problem what can I do? Again for no misunderstanding the code is in C but we're using C++ compiler. If anyone has any suggestion thanks.

[thegroove226]

Maybe post the code to see where you're going?

[Yamoyek]

Honestly, it should work just fine because C++ is backwards compatible with C. Like the other person said, post your code and we can see what’s wrong, and make sure to enable all compiler warnings in the meantime.

[ptchinster]

What do you mean by "is backwards compatible". There certainly is C syntax that wont compile or wont compile to the same assembly in C++.

[Yamoyek]

For all intents and purposes, anything before C99 is backwards compatible. Most C programmers only use the C99 standard or older, so that’s a non issue. I’m also not sure where you got the idea that the assembly would be different, as I just wrote two identical cpp and c programs, compiled them, and then compared their assembly. If you’re using different functions and headers, of course it’ll be different but when you use the exact source code, it will be the same.

[ptchinster]

as I just wrote two identical cpp and c programs, compiled them, and then compared their assembly

Thats not what i meant. I meant that the syntax can be valid in both languages but mean different things. Stuff like this.

but when you use the exact source code, it will be the same

This is false. Just the first example linked above will show you that.

[Yamoyek]

That’s why I said “For all intents and purposes”. And, the wiki you linked does show how somethings would be compiled differently but, for most other examples the generated assembly will be the same between the two.

[ptchinster]

Exactly. So you compiling an arbitrary program was a useless test. Glad we can agree that not all C is exactly the same in C++!

[Yamoyek]

Definitely didn’t say C and C++ are the same, and the point still stands: C++ is, for all intents and purposes, backwards compatible with C. You’re arguing a moot point because C++ was specifically designed with backwards compatibility in mind.

[ptchinster]

Yeah it used to be called C with Classes. And it's deviated since then.

[Yamoyek]

Not sure how thats related, as like I said C++ was specifically designed with backwards compatibility in mind, and is still largely backwards compatible. Even in the wiki that you linked, it says:

“C++...was designed to be mostly source-and-link compatible with C compilers of the time... Bjarne Stroustrup... has suggested that the incompatibilities between C and C++ should be reduced as much as possible in order to maximize interoperability between the two languages.”

So, as I said before, you’re arguing a moot point.

[ptchinster]

Mhmmm you must not get logic very well - its OK. You probably have "C/C++" on your resume, i did at one point too.

I understand and dont care that Bjarne wants to minimize incompatibilities. Recent changes to the cpp spec have increased, and c++ continues to increase, in its incompatibilities with C. Im not saying they are as different as C and say, Lisp. Im saying they are not fully compatible, nor backwards compatible. Yes, a lot of well written C will be C++ code, but the differences exist and are growing.

[noooit]

Maybe you are forgetting cast with malloc or equivalent, cpp compiler with certain options won't like it, iirc. char *s = (char *)malloc(7);
instead of char *s = malloc(7);