Object-Oriented Programming →easyMultiple ChoiceObjective-mapped

1Z0-811 Object-Oriented Programming Practice Question

public class Test { public static void main(String[] args) { Animal a = new Animal(); a.sound(); } } abstract class Animal { abstract void sound(); }

Refer to the exhibit. Why does the code fail to compile?

Answer choices

Why each option matters

Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.

Correct answer & explanation

✓

Cannot instantiate an abstract class

Abstract classes cannot be instantiated. The attempt to create a new Animal() causes a compile-time error because Animal is abstract.

Answer analysis

For each option: why learners choose it and why it is or isn't the right answer here.

✗
Animal must be declared as interface
Why it's wrong here
Animal could be an interface, but the problem is specifically instantiation of an abstract class.
✗
The main method is in the wrong class
Why it's wrong here
main can be placed in any class.
✗
The sound() method is not defined
Why it's wrong here
sound() is defined as an abstract method; the error is not about missing definition.
✓
Cannot instantiate an abstract class
Why this is correct
Correct. Abstract classes cannot be instantiated directly.

Go deeper