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Hello. I'm new to programming in C and the one thing i cannot get my head around is what does things like "int *example(int a, int *b)" mean cannot you jus use "int example(int a, int b)" When a function requires parameters? Does it do this to do additional checks of different types to ensure its receiving the correct type?
I see alot of this when looking in headers and i wanna get my head around them so i can start using juicy functions :-D
Please help
Thank you all
As I like to write it:
int* example(int a, int* b)
They are pointers.
You should probably study them a bit. Incredibly basic concept in C. And also dangerous.
int * means pointer to integer data type(s). It could be single value or multi-value of integers.
http://www.cprogramming.com/tutorial/lesson6.html
When int * declared at function's parameter (e.g. int example(int a, int *b)) it means passing parameter by reference.
http://faq.cprogramming.com/cgi-bin/...1043284351#016
No, don't use the term "passed by reference." >_<
Use passed by pointer instead.
References don't exist in C (at least standard C) -- they do in C++ however. References != Pointers.
Similar but not the same.
It's a commonly used and well-accepted term. I don't see why someone shouldn't use it.Quote:
Originally Posted by Elysia
Because it's flawed and it conflicts with the C++ term references.
> Because it's flawed
How is it flawed?
> and it conflicts with the C++ term references.
I'd lean toward the side that C++ references conflict with C, since C++ references came after C pass by reference. So maybe the C++ terminology should be changed?
But I don't see much of a conflict, since they both do the same thing.
Because it is not passed by reference.Quote:
Originally Posted by robwhit
If you want to be totally correct, say it's passed by address instead. But I find pass by pointer less confusing.
You can complain to Bjarne or whoever decided it should be named references. But the point is that they are named such, and should be used by its true name.Quote:
>and it conflicts with the C++ term references.
I'd lean toward the side that C++ references conflict with C, since C++ references came after C pass by reference. So maybe the C++ terminology should be changed?
Just like we say pass by reference when we do indeed pass by reference in C++, we can equally say pass by pointer in C instead.
It's also clearer to what we're really doing.
They are not the same thing.Quote:
But I don't see much of a conflict, since they both do the same thing.
> They are not the same thing.
Right, but they both do the same thing. Any text that requires more specificity as to which mechanism is required would specify such and such as such.
Words and terms are powerful, you know. Choosing the right one can avoid a great deal of confusion.
Choosing the wrong one can have... bad effects.
And instead of writing do X in Y way like Z, I'd rather write do X.
Therefore, references are not pointers and are best separated so.
Or perhaps the next C standard could implement references the way C++ does. Why they don't have references is actually beyond me since it would save a lot of confusion and pain.
C has no references, never had them and probably never will.
Since 1978, at least - and consequently before C++ - the term "pass-by-reference" has been used to describe pointer arguments, can be found on the C ISO document, and is part of the lingo of many people who have been programming in C for more years than you can probably count.
So... just who do you think you are to change that? And since when references have the exclusive on pass-by-reference? At least, Elysia when you are corrected admit you made a mistake. I have never once saw you done that. And that's what ticks most people off. Your assertions and the fact you stick to them up to the point of it becoming ridiculous, without ever admitting you make mistakes like everybody else... I swear, you do more harm then good with that attitude of yours. And if you think you are being helpful, think again. And you owe aAudine an apology for your mistake.
You can pass arguments by reference, there is no argument.
You are passing the address, that's passing by reference.
We are not talking semantics about what it IS called. That cannot be corrected. I have merely stated it should be called "pass by pointer" rather than "pass by reference" because it is misleading, and I have suggested similar things in the past, as to avoid confusion between C and C++.
It's already a mess that we currently have two languages and two standards. Why make it worse?
And for your point about mistakes - I have done many and I have acknowledged them.
I have not made a mistake in trying to rename or change something to something else here. I have merely suggested.
However, it is clear that it is going nowhere and there will always be people on both sides of the fence - those who desire pass by pointer and those who desire pass by reference. Clearly this is leading nowhere, and I am therefore inclined to stop right here.
And when you pass the address, you pass the address, not pass by reference.
Pass by reference is correct, since this is C. The term is also applicable to assembly, and other languages.
Pass by reference is a concept, not a syntax. It is c++ that confuses things by making there be two ways to pass a parameter by reference, and only one of them is called a "reference". But again, this is C, so there is no ambiguity.
Yo are passing a reference of the variable/object.Quote:
Originally Posted by Elysia
I am not passing a reference, I am passing the address (we could just say both analogies are correct, but it MUST not be by reference). Give it a rest. This discussion leads nowhere.
(You're just jumping on this wagon because the others say "reference", aren't you?)
This is a pointless discussion.
A "reference" became a different concept in the last 20 years or so.
People argue now that Java has references, not pointers, although some argue that Java does have pointers by way of their references. C++ has references, and you can pass-by-reference.
This was part of a paradigm shift from traditional pointers to some sort of safe or easier-to-use pointer.
So, whatever.
Agreed.Quote:
Originally Posted by MacGyver
Did you open the link? They said "passing by reference"... *sob*
Btw, guys, please, I just want to explain an easy-to-understand-thing-for-beginner in my last reply.
Did you guys trying to explain something like "pass-by-reference doesn't exist in C" or "array is NOT a pointer" to someone that absolutely new to pointer?
Thanks alot for that link "audinue" i understand them now :-D.
Thanks alot to the other people who replied to my Question :-D.
Peace
Yes, we do that.Quote:
Originally Posted by audinue