Object Orientated Programming 3

Which of the following terms describes a group of objects with common properties?

• function

• event

• class

• parameter

Answer explanation

The term 'class' refers to a group of objects that share common properties or characteristics, making it the correct choice. In programming, a class defines a blueprint for creating objects with similar attributes and behaviors.

When a class is used to build an object, the object is called a(n) ___ of the class.

• method

• property

• instance

• object

Answer explanation

When a class is used to create an object, that object is referred to as an 'instance' of the class. This term signifies that the object is a specific realization of the class blueprint.

What is the term for the various characteristics of an object?

• properties

• instances

• arguments

• methods

Answer explanation

The term 'properties' refers to the various characteristics of an object, such as its attributes and behaviors. This distinguishes it from 'instances', 'arguments', and 'methods', which have different meanings in programming.

The actions that an object can perform are called ___.

• arguments

• parameters

• methods

• classes

Answer explanation

The actions that an object can perform are called methods. Methods define the behavior of an object in programming, allowing it to perform specific tasks or operations.

I want to write a shape-drawing programme to draw lots of rectangles on screen. I start the programme with the following line of code:

rect = Rectangle()

Which of the following lines of code could I add to the programme to create another instance of the class Rectangle?

• Rectangle() * 2

• rect2 = Rectangle()

• rect = Rectangle2()

• rect = rect + Rectangle()

Answer explanation

The correct choice is 'rect2 = Rectangle()' because it creates a new instance of the Rectangle class. The other options either attempt invalid operations or reference a non-existent class.

Which of the following is a mechanism by which an object acquires the properties of another object?

• Encapsulation

• Abstraction

• Inheritance

• Polymorphism

Answer explanation

Inheritance is a mechanism in object-oriented programming where one class acquires the properties and behaviors of another class, allowing for code reuse and the creation of hierarchical relationships.

The wrapping up of data and functions into a single unit is called

• overloading

• class

• object

• encapsulation 

Answer explanation

The wrapping up of data and functions into a single unit is called encapsulation. It is a fundamental concept in object-oriented programming that helps in bundling the data (attributes) and methods (functions) together.

___________ are special methods that can be used to create and initialise an object.

•  Constructors

• classes

• Interfaces

• Objects

Answer explanation

Constructors are special methods in object-oriented programming that are used to create and initialize objects. They set up the initial state of an object when it is created, making them essential for object instantiation.

Constructors are called just once when ______.

• an object is being created

• a class is being terminated

• class is being closed

• an object is being destroyed

Answer explanation

Constructors are special methods that are called when an object is being created. They initialize the object's properties and set up any necessary resources, making 'an object is being created' the correct choice.

What does an object consist of?

• Methods

• Attributes

• Methods and Attributes

• Procedures

• Variables

Answer explanation

An object in programming consists of both methods and attributes. Methods define the behavior of the object, while attributes hold its data. Therefore, the correct answer is 'Methods and Attributes'.