does java have compile time binding ??

Question

it is said that overloading have compile time binding in java but actually object created at run time so I am confused how compile time binding take place.

Answer 1

It means that the compiler works out which overload to use based solely on the compile-time type of the expressions involved. Sample code:

class Parent
{
    void foo(Object x)
    {
        System.out.println("Parent.foo(Object)");
    }
}

class Child extends Parent
{
    void foo(String x)
    {
        System.out.println("Child.foo(String)");
    }
}


public class Test
{
    public static void main(String[] args)
    {
        Child c = new Child();
        c.foo("hello"); // Calls Child.foo(String)
        Parent p = c;
        p.foo("hello"); // Calls Parent.foo(Object)
    }
}

Note how the declared type of the variable (Parent or Child for p and c respectively) determines which overloads are considered.

Note that this is not the same as overriding, which is based on the execution-time type of the target object.