What happens if you try to instantiate an abstract class?

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BlackTom AI · Accepted Answer

Starting with the general concept: an abstract class is a class that is declared with the abstract modifier and may contain abstract methods that are not implemented. Because it is incomplete by design, attempting to create an instance of it would mean constructing an object that lacks implementations for some methods, which the language rules prevent. 
Option 1: 'You can instantiate an abstract class without any issues.' This is incorrect because the language prohibits creating objects from abstract classes; they are incomplete by design and cannot be instantiated.
Option 2: 'You can instantiate an abstract class, but it will throw an AbstractMethodError at runtime.' This is also incorrect in standard language semantics; the compiler typically prevents instantiation entirely, so you would not reach runtime expecting an AbstractMethodError from a direct instantiation attempt. AbstractMethodError arises when a concrete subclass does not implement an abstract method, not when you instantiate the abstract class itself.
Option 3: 'The code will not compile, and a compilation error will occur.' This is correct. The compiler flags the attempt to instantiate an abstract class as an error, preventing compilation from succeeding.
Option 4: 'You can instantiate an abstract class, but it will be treated as a regular class without any special behavior.' This is incorrect because the class remains abstract, and the language would not allow it to be treated as a regular concrete class; its abstract status governs what you can and cannot instantiate and implement.
In summary, the key idea is that abstract classes cannot be instantiated and the compiler enforces this rule, which makes option 3 the accurate characterization of what happens during compilation.

What happens if you try to instantiate an abstract class?

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