Java overloading and overriding

Question

We always say that method overloading is static polymorphism and overriding is runtime polymorphism. What exactly do we mean by static here? Is the call to a method resolved

Answer 1

Method Overloading simply means providing two separate methods in a class with the same name but different arguments while method return type may or may not be different which allows us to reuse the same method name.

But both methods are different hence can be resolved by compiler at compile time that's is why it is also known as Compile Time Polymorphism or Static Polymorphism

Method Overriding means defining a method in the child class which is already defined in the parent class with same method signature i.e same name, arguments and return type.

Mammal mammal = new Cat();
System.out.println(mammal.speak());

At the line mammal.speak() compiler says the speak() method of reference type Mammal is getting called, so for compiler this call is Mammal.speak().

But at the execution time JVM knows clearly that mammal reference is holding the reference of object of Cat, so for JVM this call is Cat.speak().

Because method call is getting resolved at runtime by JVM that's why it is also known as Runtime Polymorphism and Dynamic Method Dispatch.

Difference Between Method Overloading and Method Overriding

For more details, you can read Everything About Method Overloading Vs Method Overriding.