AP Computer Science Vocab for Inheritance

Mutable object

Objects whose state can change after construction.

ArrayList

An array that can grow and shrink on demand, as you add (or remove) elements to the list.

IOException

An error that occurs when you read from a file.

final

A Java keyword that indicates a constant - a variable that cannot be reassigned a new value.

static

Used to describe a method or field/attribute that belongs to the class, not the object; does not require the programmer to instantiate an object in order to reference a method or field in the class.

Wrapper class

A class that wraps a primitive type in an object. These classes contain their corresponding primitive type as an instance variable, but put them into an object for situations where objects are required.

Auto-boxing

When Java automatically converts to an Object (reference) data type.

Unboxing

When Java automatically converts to a primitive data type.

Base class - super class - parent class

The class from which another class inherits properties and methods.

Derived class - Sub class - child class

The class that inherits properties and methods from a base class.

Single inheritance

Every class has 1 and ONLY 1 direct super class.

Polymorphism

The ability of a super class to store a subclass reference.

Variable hiding

When a sub class declares the same variable as its parent class.

Downcast

Casting a superclass to a subclass type.

Override

When a subclass defines the exact same method (in name and parameter list) as a method inherited from a super class.

Overload

Methods that have the same name but different parameter lists.

Super

A keyword that refers to the super-class, and can be used to call a parent class constructor or to call a parent class method.

This

A keyword in Java that refers to whatever object the keyword is found in, this object.

Root Class

The Java class at the top of the Java class hierarchy.

Constructor chaining

Use this() to call other constructors in the same class.