How is the initialization of classes related to memory allocation?

During the initialization of a class object, memory is allocated for its storage. This process includes the following steps:

1. Size calculation: The system determines the amount of memory needed to store all the properties of the class instance and metadata (e.g., a pointer to the virtual method table).
2. Memory request: The system sends a request to allocate the necessary size of memory from the heap.
3. Memory allocation: If enough free space is available, the heap allocates a block of memory and returns a pointer to it.
4. Calling the initializer (init): After obtaining a pointer to the allocated memory, the system calls the class's initializer (init) to set up the initial state of the instance's properties. Additional resources may be allocated or other objects created during initialization.
5. Returning the instance: The initializer completes, and the system returns a reference to the created and initialized class instance.

The allocated memory remains occupied until the object is released by the memory management system (Automatic Reference Counting - ARC in iOS).

Example:

class MyClass {  
    var number: Int  
    var text: String  

    init(number: Int, text: String) {  
        // At this stage, memory for the instance has already been allocated.  
        self.number = number // Assigning value to property  
        self.text = text     // Assigning value to property  
        // The initializer finishes, and the object is ready to use.  
    }  
}  

// Creating an instance of MyClass.  
// Memory is allocated, and init() is called.  
let myObject = MyClass(number: 42, text: "Hello")