Compile-time error: cannot have constructor in abstract class

Creating Superclasses and Subclasses

AP Computer Science A· difficulty 4/5

public abstract class A {
    public A() { System.out.print("A "); }
    public abstract void f();
}
public class B extends A {
    public B() { System.out.print("B "); }
    public void f() { System.out.print("f "); }
}
A x = new B();
x.f();

What is printed?

A
$f A B$
B
$A B f$
check_circle
C
$Compile-time error: cannot have constructor in abstract class$
D
$B A f$

Explanation

Abstract classes CAN have constructors (called via super). A's constructor runs first, then B's, then f().

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