If you have experience in other programming languages, such as Java, and are coming to Objective-C now, forget about constructors, they don't exist in Objective-C. Constructors are language-level constructs that merge the allocation and initialization actions, but they have restrictions:
They don't return anything. While the Objective-C class initialization method, + (
void) initialize, does not return anything, the default—(id)initmethod of an Objective-C class returns an object of the typeid.The constructor's name must be identical with the class.
When you call the superclass, being the first statement is a must.
The last point ensures you won't deal with garbage data, but this is a restriction. In Objective-C, as in C, without this restriction, you, the programmer, have more flexibility and power, but it is also your responsibility to deal with garbage data.