FRQ 3 Array and ArrayList

Recently, I've heard many say that Unit 9: Inheritance of the AP CSA course and exam description has been "entirely removed". I even saw a graphic on Reddit with these exact words. But that isn't "entirely" true. While inheritance has been descoped and it is true that student do not need to implement inheritance, there are still some inheritance that needs to be taught. Be sure to read the course and exam description carefully.

Where Is Inheritance in the 2025 - 26 Course Update?

I will be referencing essential knowledge statements in both the 2020 AP CSA Course and Exam Description and the 2025 AP CSA Course and Exam Description that is current starting in the 2025 school year. Former versions of Essential Knowledge statements will start with MOD, while current Essential Knowledge statements will start with a 1.

In the, 2025 Course and Exam Description, find Essential Knowledge statement 1.12.A.2. It states:

1.12.A.2 A class hierarchy can be developed by putting common attributes and behaviors of related classes into a single class called a superclass. Classes that extend a superclass, called subclasses, can draw upon the existing attributes and behaviors of the superclass without replacing these in the code. This creates an inheritance relationship from the subclasses to the superclasses.

What? Subclasses and superclasses still alive in the CED? Yep! As a matter of fact, this Essential Knowledge statement is a combination of the following Essential Knowledge statements in the prior version of the CED and a modified positioning of the learning objective.

• Mod 3.B.1 A class hierarchy can be developed by putting common attributes and behaviors of related classes into a single class called a superclass.
• MOD 3.B.2 Classes that extend a superclass, called subclasses, can draw upon the existing attributes and behaviors of the superclass without repeating these in the code. And that's the entire second sentence.

And now for something a little subtle, a shift from the Learning Objective from having to create these these relationships, to knowing that inheritance creates this relationship.

• MOD-3.B Create an inheritance relationship from a subclass to the superclass.

So, in summary, the new EK 1.12.A.2 is a combination of MOD-3.B.1, MOD-3.B.2, and MOD-3B.

Where else do we see inheritance topics in the new CED?

Let's look at Essential Knowledge statement 1.12.A.3. It states:

1.12.A.3 All classes in Java are subclasses of the Object class. This essential knowledge statement comes from the following former Essential Knowledge statement:

• MOD 3.E.1 The Object class is the superclass of all other classes in Java. Slightly re-worded, but the sentiment is definitely preserved.

One more place where we see inheritance in the new CED.

There is one more Essential Knowledge statement that comes from the former Unit 9 on Inheritance.

1.15.A.5 A String object can be concatenated with any object, which implicitly calls the object's toString method (a behavior that is guaranteed to exist by the inheritance relationship every class has with the Object class.) An object's toString method returns a string value representing the object. Subclasses of Object often override the toString method with class-specific implementation. Method overriding occurs when a public method in a subclass has the same method signature as a public method in the superclass, but the behavior of the method is specific to the subclass.

The inheritance topic of method overriding comes in the second half of this Essential Knowledge statement. This Essential Knowledge statement is partially comprised of the following two former Essential Knowledge statements.

• MOD 3.B.10 Method overriding occurs when a public method in a subclass has the same method signature as a public method in the superclass.
• MOD 3.E.4 Subclasses of Object often override the equals and toString methods with class-specific implementations.

What's The Best Way to Teach These Topics?

You might want to provide students with some examples of simple superclass and subclass relationships. It's OK to expose them to some code that is beyond the course to illustrate what is meant in these Essential Knowledge statements. You can also have students write toString methods for their classes and show them what the compiler does if you do not override this method.

Happy Java Coding and Read the New CED for Yourself!