Structures are very useful. They allow you to organize your data in one place, and retrieve it in a way that makes sense.

How to define a structure

Put this code in your implementation file between your import lines and your @implementation line. – I think this is right. Is it? What if it is declared in between the braces in the header file, then where do you define it?

struct myStruct { short myInteger; long myLongInteger; float myFloatingPointValue; };

How to declare structure

Put this code wherever you would normally declare a variable. In other words, put it in a method in your implementation file, or between the braces in your header file.

struct myStruct s;

How to add values to a structure

s.myInteger = 7; s.myLongInteger = 437090; s.myFloatingPointValue = 53.467;

Note : Adding something about how to initialize structures seems appropriate here.

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If you want to avoid putting “struct” in front of all your struct variables (i.e., “struct myStruct s”) you can typedef your struct as something else:

struct myStruct { short myInteger; long myLongInteger; float myFloatingPointValue; }; typedef struct myStruct myStruct;

struct myStruct gStruct1; // this global variable reference is ok myStruct gStruct2; // this global variable reference is also ok

This typedef is commonly done on one line:

typedef struct { short myInteger; long myLongInteger; float myFloatingPointValue; } myStruct;

Also, this topic is all covered in Kernighan & Richie’s “The C Programming Language”, a book every C-based programming-language programmer should memorize.

Also, for the love of Pete, can we StopUsingMyInVariableNames? This probably goes without saying, but it’s a very bad habit.

– MikeTrent

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