Polymorphism

AP Computer Science A· difficulty 4/5

public class A {
    public String x() { return "A.x"; }
    public String y() { return x(); }
}
public class B extends A {
    public String x() { return "B.x"; }
}
public class C extends B {
    public String y() { return "C.y"; }
}
// Usage:
A obj = new C();
System.out.print(obj.y());

What is printed?

A
$A.x$
B
$C.y$
check_circle
C
$B.x$
D
$Compile error$

Explanation

Dynamic dispatch picks the most-derived override of y, which is C's y returning "C.y".

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