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Why do they have the structure like this:
When they could have left out 'telephone'. E.g.Code:typedef struct telephone { char *name; int number; }TELEPHONE;
Thank you for any help given, this has been ........ing me off for a while.Code:typedef struct //Minus the 'telephone' { char *name; int number; }TELEPHONE;
The first form defines a type named "struct telephone", and TELEPHONE as a pseudonym for that.
The second form makes TELEPHONE a pseudonym for an anonymous struct type.
Practically, the difference is usually one of coding style and preference. Some people prefer to declare instances of the structure using "struct telephone a_phone" so they are explicitly documenting that a_phone is a data structure, not some other type.
If you wanted to have a pointer of that struct type as a member of the struct, then you need struct telephone, not just an anoymous struct. So, this might be a matter of consistency, or it might even be as simple as a matter of copy/paste or habit.Originally Posted by inu11byte
By the way...
Although there are instances of such a style being used (FILE comes to mind), generally the convention is to reserve fully capitalised names for macros and constants.The name of the type definition of a structure is usually in uppercase letters.
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How come if I remove the 'typedef', I have to change the 'TELEPHONE' to lower-case? E.g.
Code://#includes struct telephone { char *name; int number; }TELEPHONE; int main() { struct telephone index; struct telephone index2; //rest of code.
This defines a structure of type struct telephone, and an instance of that called TELEPHONE.Code:struct telephone { char *name; int number; }TELEPHONE;Those make two more instances of struct telephone called index2 and index.Code:struct telephone index; struct telephone index2;
Quzah.
Hope is the first step on the road to disappointment.
Because you wrote struct telephone instead of struct TELEPHONE. By the way, since you did not remove the TELEPHONE from after the struct definition, you ended up with a variable named TELEPHONE of the struct type.
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Okay, now I understand it. Thank you everyone for the help. I could have done it without properly understand how/why things are the way they are, but that's not the programmer way. Plus, it would have annoyed me.
I applaud your sentiment here (I prefer to properly understand things where I can too). However, unfortunately, doing something without proper understanding is the "programmer way" all too often.
Isn't that what abstractions are all about? (To not have to understand the boilerplate details of something ?)
Not precisely. Abstractions are alternative ways of thinking about particular aspects of a problem, and solutions to it. You are right that abstractions can be used to shield you from lower level details. But you still need to understand the abstractions, even if you don't understand the low level details that underpin them.
As evidence of my original point: how many times in this forum alone do you see people using pointers with limited or no understanding of what pointers are? A pointer is an abstraction, albeit a low level one, that shields the programmer from details such as how the processor interacts with RAM.
