CODEWITHSUNDEEP
javacasting
device
device

Reputation: 105

Upcast in Java Difference

class A {
}

class B extends A {
}

class Main {
    public static void main(String[] args) {

        B b1 = new B();
        B b2 = new B();

        A a = b1;
        A c = (A) b2;
    }
}

Is there any difference between a and c? b1 is directly referenced and b2 is upcasted to A and then referenced to c of type A.

Upvotes: 2

Views: 63

Answers (2)

T.J. Crowder
T.J. Crowder

Reputation: 1075309

There's no need for the cast there. In an assignment context, a widening reference conversion is allowed. No need for a casting context. (Now, if it were a narrowing reference conversion, you'd have to do that explicitly.)

Upvotes: 3

Mureinik
Mureinik

Reputation: 312086

The cast is redundant. b2 gets assigned to c regardless, and invoking any methods on it will invoke the methods of B if they exist.

Upvotes: 2

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