Objects and Classes

Question 1

What are objects?

Answer 1

They’re program modules that can do actions or be acted upon by other objects.

Question 2

What are properties and behaviours of objects?

Answer 2

Properties are data about the object, such as attributes or fields or instance variables. While behaviours are methods, like instance methods.

Question 3

What has to happen before an instance method is called?

Answer 3

An object of that class must be called before a method of its class can be called upon it.

Question 4

What’s an analogy for a class?

Answer 4

A template, model or definition for objects of that class.

Question 5

Does every object belong to a specific class?

Answer 5

Yes, and objects that belong to the same class have the same properties and can perform the same actions.

Question 6

What do Object-oriented programs consist of?

Answer 6

Interacting objects, namely objects that are defined by classes and can be created by objects of other classes (client classes). Typically used in implementing a programming solution to a problem.

Question 7

What does a class definition consist of?

Answer 7

Attribute declarations (instance/field variables), Constructor definitions, Method definitions

Question 8

How is a class definition stored?

Answer 8

In a file with the same name as the class and a .java extension.

Question 9

Describe the Software Life Cycle

Answer 9

1. Problem specification
2. Design (algorithms and data structures)
3. Implementation (translate design into code)
4. Testing and debugging.

Question 10

Describe Modular Design

Answer 10

Breaking a complex problem into smaller isolated problems, (modules). Each module contains data and code, part of a module is kept hidden from other modules to achieve independence (private and public).