Inheritance (object-oriented programming)
In Object-oriented programming languages, inheritance is a way to add functionality. Object-oriented programming has the notion of classes (and perhaps interfaces). A derived class inherits most fields and methods from its parent class. It can modify the behaviour of the parent, by adding new fields and methods, or by modifying existing ones. Depending on the programming language used, there may be certain restrictions when extending a class.
Inheritance can be used to solve different types of problems:
- Specialisation: The child class extends the functionality of the parent. That way a Bank account may have fields for balance, account number and owner; a subclass interest-earing account may add fields like interest rate and interest received.
- Overriding: The child class can redefine the behaviour of the parent class.
- Code reuse: Code that is common to many classes can be placed in a parent class, and reused.
