A brief introduction, implementation, benefits, and limitations of method overridingMethod overriding is a feature that allows a subclass, or a child class, to specifically implement a method already given in one of its super-classes, or parent classes, in any object-oriented programming language. Show
Thus, the process of redefining a parent class’s method in a subclass is known as method overriding. It is also called run time polymorphism or dynamic binding because the compiler doesn’t really know the type of object passed on compilation. When a method in a subclass has the same name, parameters or signature, and return type (or sub-type) as a method in its super-class, then the method in the subclass (the child class) overrides the method in the super-class (the parent class). We can implement method overriding in any object-oriented programming language, but only when the classes involved have an ‘IS-A’ relationship of inheritance between them. In the illustration above, the
In the above example, the Dog class gives its own implementation of the Method overriding and dynamic method dispatchTo accomplish Java runtime polymorphism, overriding methods are utilized. The object that is used to call the method determines the version of the method that is being run. When a method is called with an object from a superclass, the parent class’s version is executed, but when a method is called with an object from a subclass, the child class’s version is executed. That is, which version of the overridden method is performed is determined by the type of the referenced object (not the type of the referenced variable). The practice of resolving overridden method calls at runtime is known as dynamic method dispatch. To understand this, see the example below:
In the example above, the
Inheritance and final keywordFor method overriding to happen, there has to be an IS-A relationship between a baseclass and a subclass. This is known as inheritance in OOP concept. When there is an IS-A relationship between two classes, the child class can therefore override the methods it inherits from the base class. During inheritance, we have to declare methods with the final keyword which we required to follow the same implementation throughout all the derived classes. When a method is declared as final, it cannot be overridden by subclasses. The classes that extend from a base class that have methods with final keywords can only implement the method same way it was in the super class. Covariant in method overridingIf a subclass overrides any method with a Non-Primitive return type, the method can be overridden by modifying the return type. It is possible for a child class to have a distinct return type for an overriding method, but the child’s return type must be a sub-type of the parent’s return type.
Benefits of method overriding in Java
Method overriding limitations
What is the process of defining a method in subclass Having Same name & type signature as a method in its superclass?Method overriding is when a subclass redefines a method of its superclass, of course the redefined method (of the subclass) has the same name and the same parameter types of the method of its superclass.
Which is process of defining two or more methods within same class that have same name but different parameters declaration?The practice of defining two or more methods within the same class that share the same name but have different parameters is called overloading methods.
What is the process of defining a method in terms of itself that is a method that calls itself?Recursion is the process of defining something in terms of itself. It allows us to define method that calls itself repeatedly until it meets some base case condition.
Which of this keyword can be used in a subclass to call the constructor of superclass?The super keyword refers to superclass (parent) objects. It is used to call superclass methods, and to access the superclass constructor.
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