What does self mean in Objective-C?

What does self mean in Objective-C?

current object reference
The self in Objective-C is the current object reference, other OO languages call it this – both Java and C++ use that name. Understanding objects and methods is fundamental to using any of these languages.

What is class method in Objective-C?

In Objective-C, a class method is denoted by a plus (+) sign at the beginning of the method declaration and implementation: + (void)classMethod; To send a message to a class, you put the name of the class as the receiver in the message expression: [MyClass classMethod];

What is super in Objective-C?

Messages sent to an object’s superclass (using the super keyword) are sent using objc_msgSendSuper; other messages are sent using objc_msgSend. Methods that have data structures as return values are sent using objc_msgSendSuper_stret and objc_msgSend_stret. So yes, it is static, and not determined at runtime.

Is there a self keyword in C++?

In some languages, for example C++ and Java, this or self is a keyword, and the variable automatically exists in instance methods. However, by informal convention, the first parameter of an instance method in Perl or Python is named self .

What is Ivar Objective-C?

Refer to Propety, Instance Variable and @synthesize. …

What is the use of self in Swift?

self is a property on the instance that refers to itself. It’s used to access class, structure and enumeration instance within methods. When self is accessed in a type method ( static func or class func ), it refers to the actual type (rather than an instance).

What is the difference between class method and instance method?

Instance method performs a set of actions on the data/value provided by the instance variables. If we use instance variables inside a method, such methods are called instance methods. Class method is method that is called on the class itself, not on a specific object instance.

What’s the difference between class methods and instance methods?

Key Takeaways Instance methods need a class instance and can access the instance through self . Class methods don’t need a class instance. They can’t access the instance ( self ) but they have access to the class itself via cls .

How do you inherit a class in Objective C?

When creating a class, instead of writing completely new data members and member functions, the programmer can designate that the new class should inherit the members of an existing class. This existing class is called the base class, and the new class is referred to as the derived class.

What is self super init?

In the subclass (your class that you’re working on) you call self = [super init] What this basically does is calls the super class’s (the ones I mentioned above) init method (the constructor) and assigns it to the current class. This makes sure that the superclasses’ initializing method is called.

Can a class have an object of itself?

A class declaration can contain static object of self type, it can also have pointer to self type, but it cannot have a non-static object of self type. For a compiler, all pointers have a fixed size irrespective of the data type they are pointing to, so no problem with this also.

Can a class have a member of its own type?

Because in Java, a variable of type abc doesn’t contain an abc object. A variable of type abc contains a reference to an abc object. Your reasoning would be valid in say C++. But a class can have static object of self type.

Can a C++ class have an object of self type?

Can a C++ class have an object of self type? A class declaration can contain static object of self type, it can also have pointer to self type, but it cannot have a non-static object of self type. For example, following program works fine. And following program also works fine.

What is a static method in Objective-C?

From Wikipedia: Static methods neither require an instance of the class nor can they implicitly access the data (or this, self, Me, etc.) of such an instance. This describes exactly what Objective-C’s class methods are not. An Objective-C class method very much requires an instance that is the target of the method invocation.

Can a class declaration contain an object of self type?

A class declaration can contain static object of self type, it can also have pointer to self type, but it cannot have a non-static object of self type. For example, following program works fine. using namespace std;

Can a class have a non-static member of self type?

A class declaration can contain static object of self type, it can also have pointer to self type, but it cannot have a non-static object of self type. For example, following program works fine. // A class can have a static member of self type.