Question

I want to create a Zoo class, which keeps track of all the animals in the zoo using an Animal class. Would inheritance make sense here? Why, or why not? Explain your reasoning clearly.

Answer 1

What is Inheritance:

• Inheritance is a mechanism wherein a new class is derived from an existing class.
• Classes may inherit or acquire the properties and methods of other classes.
• Derived class: A class that inherits another class is known as derived class or sub class or child class.
• Base class: The class that is being inherited by other class is known as base class, super class or parent class.
• Following diagram demonstrate inheritance.

​​​Since you want to make a class Zoo and for that class Inheritance make sense.

• First of all we will create the Animal base class.
• The central idea is that we have a group of animals living inside a zoo.
• This group of animals consists of Lions, Tigers, Cats, Hippos, Wolfs , Dogs and many more.
• They can do certain things like sleeping, roaming, making noise or eating.
• Along with these things that they can do they also carry specific characteristics like the kind of food they prefer (meat or grass), how much hungry they are at a specific moment and their location in the zoo.
• One picture of every animal. This is also a key characteristic of every animal.

Using any programming language of your choice you can create a base class Animal and inherit other class like Dogs, Lions etc from the base class.

For example,

Step 1:

a) First step is to create a base class Animal.

b) In this class define some methods e.g. sleep, roam, eat etc. which are common to all the animals.

c) Define some properties which are common to all the animals e.g. food, hunger, picture etc.

d) Refer the diagram:

​​​​​​

Step 2:

​​​​​​a) Create another class e.g. Lion, Cat, Dog, Hippo.

b) For this derived class, you can inherit the methods and properties defined in the base class.

c) Refer the diagram:

Step 3:

Using this inheritance concept you can create multiple classes and reuse the methods and properties defined in the base class.

Advantages of using inheritance:

• Promotes code reusability.
• When a class inherits or derives another class, it can access all the functionality of inherited class.
• Reusability enhanced reliability. The base class code will be already tested and debugged.
• Since the existing code is reused, it leads to less development and maintenance costs.
• Inheritance makes the sub classes follow a standard interface.
• Helps to reduce code redundancy and supports code extensibility.
• Facilitates creation of class libraries.