Overloading is compile-time polymorphism. Really?

Question

I do know the syntactical difference between overriding and overloading. And I also know that overriding is run-time polymorphism and overloading is compile-time polymorphis

Answer 1

What is polymorphism?

Acc. to me: if an entity can be represented in more than one forms, that entity is said to exhibit polymorphism.

Now, lets apply this definition to Java constructs:

1) Operator overloading is compile time polymorphism.

For example, + operator can be used to add two numbers OR to concatenate two strings. it's an example of polymorphism strictly saying compile-time polymorphism.

2) Method overloading is compile time polymorphism.

For example, a method with same name can have more than one implemntations. it's also a compile-time polymorphism.

It's compile-time because before execution of program compiler decides the flow of program i.e which form will be used during run-time.

3) Method overriding is run-time polymorphism.

For example, a method with same signature can have more than one implemenations. it's a run time polymorphism.

4) Base class use in place of derived class is run time polymorphism.

For example, an interface reference can point to any of it's implementor.

It's run-time because the flow of program can't be known before execution i.e. only during run-time it can be decided that which form will be used.

I hope it clears a bit.