Help with understanding C# code and porting to Objective-C

Question

Ok, I have this prototype that was written by someone else in C# and I\'m trying to put it into Objective-C. Now, I haven\'t had any formal experience with C# yet, so I don\

Answer 1

The 4th line is a parameterless constructor and the 5th line is a parameterfull constructor.

Answer 2

The fourth and fifth lines are constructors in C#. They are the equivalent to [[c_data alloc] init] chains in objective-c. C# allows you to overload constructors based on the parameters they take. This is equivalent to having two different initialization methods in Objective-C:

@interface CData : NSObject
{
   double value;
   int label;
   int ID;
}

@property double value;
@property int label;
@property int ID;

-(id) init;
-(id) initWithValue:(double)value;

@end

Answer 3

The first c_data is a default no-args constructor which initialises the structure's fields to default values (value -> 0.0, label -> 0, ID -> 0) and the second c_data is a constructor which sets the value field of the instance to the passed-in parameter val and the other fields to their default values. What I've described is how those two constructor calls initialise the instance.

Answer 4

If I may, it is rather like the having both the following methods in an Objective-C class:

• (id)init;
• (id)initWithNumber:(NSNumber *)number;

Constructors and initializers are analogues, they just look a little different.

Answer 5

4th and 5th are constructors that are used to initialize the instance of c_data when you new up one.

Answer 6

The fourth is defining a constructor for the class which takes no parameters and has no actions, and the fifth is defining a constructor for the class which takes as a parameter a double value and which sets the class-internal member variable value to the passed value val.