Swift’s static and class methods are similar in that they are both called on the type itself, rather than an instance of the type. However, they have distinct differences primarily in how they interact with subclassing:

  1. Static Methods:
    • Inheritance: Static methods are not inheritable. They are tied to the class in which they are defined. If you define a static method in a parent class, it will not be available in any subclass.
    • Overriding: Since static methods are not inherited, they cannot be overridden in a subclass.
    • Use Case: Static methods are typically used for utility functions that are closely tied to a particular type but do not need to access any instance-specific data.
  2. Class Methods:
    • Inheritance: Class methods are inheritable. If you define a class method in a parent class, it can be accessed from any subclass.
    • Overriding: Class methods can be overridden in a subclass. This allows you to provide subclass-specific behavior while maintaining a common interface.
    • Use Case: Class methods are used when you need a method that is related to the class but also has the flexibility to be influenced by subclasses. They are common in class hierarchies where subclasses might need to provide their own implementation of the method.

In summary, static methods are best when you need a method that is tied to a class and does not need to be modified by subclasses. Class methods, on the other hand, are more suitable when you want the method to be part of a class’s interface that can be customized by subclasses.

From ChatGPT