IBCS P2 Vocab

Basically Topic 4 and answers to past paper questions.

Nature of an Object

Contains attributes and behaviours. Defined by a class.

Class

The blueprint from which an object is created, defining the attributes and behaviours of the object.

Instantiation

Process of using a class constructor to create an object. Uses keyword new.

Inheritance (is-a)

Solid line and hollow arrowhead from child to parent. Allows a class to have the behaviour and attributes of another class.

Aggregation (has-a)

Relationship between two classes where an object of one class has an object of another. Solid line with unfilled diamond closest to the container class.

Dependency

Exists between two classes if the changes to the definition of one may cause changes to the other (but not the other way around). Dashed line with open arrow.

Why are dependencies bad?

• Decrease reuse

  • Reduces development speed

  • Reduces code quality

  • Reduces code readability

  • Harder to maintain code

How can dependencies be reduced?

Interfaces and abstract classes → reduces coupling to one single class. Now applies to “umbrella” of classes.

Encapsulation

The process of combining variables and methods in a single package called a class

Data type

Specifies the size and type of values that can be stored in an identifier or variable

Polymorphism

A programming languages ability to handle different data types with the same interface. This presents as:

• Method Overloading

• Method Overriding

Method Overloading

Occurs at compile time. Defining more than one method with the same name (constructor).

Method Overriding

Occurs at run time. The ability to redefine methods for subclasses (inheritance).

Advantages of Polymorphism

• Common Interface → one name for multiple implementations.

• Extensibility → programs can handle new types of data without restructuring existing code.

• Code Reuse → common interface, so methods can be reused.

• Simple maintenance → reduces complex statements → cleaner code + easier to debug

Advantages of Encapsulation

• Simplifies interaction between objects.

• Hides the internal details of how an object does something.

• A class can change its internal implementation without hurting the overall functionality of the system.

• Prevents code from accidental corruption due to programming errors.

Advantages of Inheritance

• Code Reuse → don't have to rewrite common code.

• Extensibility → code is well structured so easier to expand or update.

• Easier Maintenance → code is well structured so it is easier to maintain.

Advantages of code libraries

• Increased productivity → programmers don't have to "reinvent the wheel."

• Efficient code → code is typically stable and optimized.

• Code reuse

Disadvantages of OOP

• Size → programs are generally larger than normal programs.

• Speed → generally slower than normal programs.

• Effort → programs require a lot more time and effort to create.

• Learning → there is a larger learning curve when it comes OOP development.

Modularity

The process of creating software modules/sub-programs that can then be combined.

Use of programming teams

Team approach → multiple programmers working on the same piece of source code allows strengths to make up for collective weaknesses; also increases productivity with share responsibilities.

Advantages of modularity

• Code reuse

• Easier maintenance → easier to debug, modify

• Better usability —> easier to read

• Increased production → makes program development faster

Internationalisation

The Unicode character set has a set large enough to store every language in the world. Program’s UI can be customised to meet the needs of users.

Moral and Ethical obligations of programmers

Advantages of Open Source Movement

• Collaborative and transparent approach

• Software is more accessible

• More affordable/cost-effective solutions

• Software is more flexible/tailored to needs → higher quality

Object reference

A variable that stores the memory address of an object.

Advantages of binary tree over static array

• Faster searching

• Memory efficient

• Can grow and shrink dynamically

• Supports ordered storage → efficient retrieval

Disadvantage of binary trees

• Uses more memory → each node stores extra pointer

• Deleting a node is complex

• Trees require careful pointer management/maintenance

Disadvantages of Open Source Movement

• Security risks with openly accessible code

• Leads to licence violations and propriety issues

Applications of Circular Linked Lists

• Playlist

• Round-robin scheduling

• Implement queue/dequeue

• Image galleries

Applications of Queues

• Printer queue

• Storing client service requests

• Multitasking OS/Scheduling → manage multiple processes

Applications of Stacks

• Parsing expressions in compiler

• Supporting the ‘undo’ feature

• History of links in Web browser