No visible @interface for 'class' declares the select 'method' when calling super

Question

I have the following code,

In .h file:

@interface MyBaseClass : NSObject
{
    - (void)myMethod;
}

In .m file:

@implementation MyClass2000 : MyBaseClass
{
    - (void) myMethod
    {
        //Does something interesting here
        myData[0] = 0;
        myData[1] = 1;
    }
}

Later I created a class that extends "MyClass2000" and is called "MyClass2001"

.h file:

#import "MyClass2000.h"

@interface MyClass2001 : MyClass2000
@end

.m file:

@implementation MyClass2001 : MyClass2000
{
}

This class is exactly the same as "MyClass2000" (but I specifically need to keep them in separate classes, and one extending the other. I also need a "MyClass2002 class", which in this case will need to update only 1 of the indexes, so I tried to call [super myMethod] as follows:

The next class extends "MyClass2001"

.h file:

#import "MyClass2001.h"

@interface MyClass2002 : MyClass2001
@end

.m file:

@implementation MyClass2002 : MyClass2001
{
    - (void) myMethod
    {
        [super myMethod];

        //Only update one value
        myData[1] = 1;
    }
}

On that line I'm getting: No visible @interface for 'MyClass2001' declares the selector 'myMethod'.

Any tips on how to get this to work?

Thanks!

Answer 1

That isn't how you declare a method in Objective-C. In your interface, you declare the method like this:

@interface MyClass2000 : MyBaseClass {
    NSString *someVariableDeclaration;
}

- (void) myMethod;

@end

And then you implement the function in your .m like this:

@implementation MyClass2000 {
    NSString * someDifferentVariableDeclaration;
}
 - (void) myMethod
{
    //Does something interesting here
    myData[0] = 0;  
    myData[1] = 1;
}
@end

Answer 2

Where you have the line:

[super MyClass2001];

Instead you want to have:

[super myMethod];

You were trying to call a method named MyClass2001, which doesn't exist.

Answer 3

1.Jus check the Inheritance hierarchy. In Objc its necessary to have implementation for every interfaces. But your code tells you don't have MyBaseClass implementation.

2.Method declaration cant be done inside {} in .h.

3.Method definition cant be done inside {} in .m.

4.Implementation does not extended only interface be extended.

It should work if proper hierarchy maintained.