Inheritance What is inheritance Isa vs Hasa relationship

Inheritance A class (child class) – inherits the functionality of another class (parent class),

Why inheritance? • Inheritance is a technique for reuse. • If a new class

Inheritance (an is-a relationship) • Inheritance is a parent-child relationship between classes. • The

Example: Inheritance Diagram Mammal Dog Cat Base Class Subclasses of Mammal Border Collie 5

Example: In an OOP traffic simulation, you may have the following classes: Make an

Important Concept in OOP!!! “Is-a” Inheritance 7 vs. “Has-a” Instance variables (private data) of

Example: The Circle. Bug A Circle. Bug will inherit most of the qualities of

Example: Create a checking account class. A checking account has all of the qualities

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Inheritance - What is inheritance? - “Is-a” vs. “Has-a” relationship - Programming example “Circle. Bug” 1 AP Computer Science A – Healdsburg High School

Inheritance A class (child class) – inherits the functionality of another class (parent class), and then – adds new functionality of its own. • Java supports single inheritance. • Inheritance is a requirement of all object-oriented systems. 2 AP Computer Science A – Healdsburg High School

Why inheritance? • Inheritance is a technique for reuse. • If a new class has a lot in common with a class that already exists, you can reuse parts of the existing class in the new class. • The child class is defined by extending the parent class. • The new ''child'' class has all characteristics of its ''parent'' plus any it adds itself. 3 AP Computer Science A – Healdsburg High School

Inheritance (an is-a relationship) • Inheritance is a parent-child relationship between classes. • The parent class is also called a base class or a superclass. • The child class is also called a derived class or subclass. 4 AP Computer Science A – Healdsburg High School

Example: Inheritance Diagram Mammal Dog Cat Base Class Subclasses of Mammal Border Collie 5 AP Computer Science A – Healdsburg High School

Example: In an OOP traffic simulation, you may have the following classes: Make an inheritance diagram for the classes at the left. -Vehicle -Car -Truck -Sedan -Coupe -Pickup. Truck -SUV -Minivan -Motorcycle -Bicycle 6 AP Computer Science A – Healdsburg High School

Important Concept in OOP!!! “Is-a” Inheritance 7 vs. “Has-a” Instance variables (private data) of a class AP Computer Science A – Healdsburg High School

Example: The Circle. Bug A Circle. Bug will inherit most of the qualities of a Bug. The only difference is how this bug moves. A Circle. Bug acts identical to the Box. Bug, except that in the act method, the turn method is called once instead of twice. How is the behavior different than a Box. Bug? Should it be called a Circle. Bug? Inheritance Diagram Bug Circle. Bug 8 AP Computer Science A – Healdsburg High School

Example: Create a checking account class. A checking account has all of the qualities of a Bank. Account, but is assessed a fee of $2. 00 if there are more than 3 transactions per month. Inheritance Diagram Bank. Account Savings. Account 9 Checking. Account AP Computer Science A – Healdsburg High School