IB Computer Science Topic B3.2.5 Explaining Commonly Used Design Patterns in OOP Revision Notes (HL) | RevisionDojo

Commonly Used Design Patterns in OOP

What Are Design Patterns?

Design patterns are reusable solutions to common software design problems.
Their purpose is to provide best practices for creating scalable, maintainable, and flexible code.
Their benefit is that they save time, improve communication between developers, and avoid reinventing the wheel.

Key Patterns in the IB Syllabus

Singleton Pattern

Goal: Ensure only one instance of a class exists in the system.
When Used:
1. Database connections
2. Configuration settings

Example

Java:

class Database {
    private static Database instance;
    
    private Database() {}   // private constructor
    
    public static Database getInstance() {
        if (instance == null) {
            instance = new Database();
        }
        return instance;
    }
}

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Note

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Tip

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Lorem ipsum dolor sit amet, consectetur adipiscing elit.
Sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.
Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris.
Duis aute irure dolor in reprehenderit in voluptate velit esse cillum.

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Commonly Used Design Patterns in OOP

What Are Design Patterns?

Design patterns are reusable solutions to common software design problems.
Their purpose is to provide best practices for creating scalable, maintainable, and flexible code.
Their benefit is that they save time, improve communication between developers, and avoid reinventing the wheel.

Key Patterns in the IB Syllabus

Singleton Pattern

Goal: Ensure only one instance of a class exists in the system.
When Used:
1. Database connections
2. Configuration settings

Example

Java:

class Database {
    private static Database instance;
    
    private Database() {}   // private constructor
    
    public static Database getInstance() {
        if (instance == null) {
            instance = new Database();
        }
        return instance;
    }
}

Definition

Paywall

(on a website) an arrangement whereby access is restricted to users who have paid to subscribe to the site.

anim nostrud sit dolore minim proident quis fugiat velit et eiusmod nulla quis nulla mollit dolor sunt culpa aliqua

Duis aute irure dolor in reprehenderit

Note

Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam quis nostrud exercitation.

Excepteur sint occaecat cupidatat non proident

Tip

Lorem ipsum dolor sit amet, consectetur adipiscing elit.
Sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.
Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris.
Duis aute irure dolor in reprehenderit in voluptate velit esse cillum.

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A1 Computer fundamentals4 subtopics

A2 Networks4 subtopics

A3 Databases4 subtopics

A4 Machine learning4 subtopics

B1 Computational thinking1 subtopic

B2 Programming5 subtopics

B3 Object-oriented programming2 subtopics

B4 Abstract data types (HL only)1 subtopic

IB Computer Science Topic B3.2.5: Explaining Commonly Used Design Patterns in OOP Notes

A1 Computer fundamentals4 subtopics

A2 Networks4 subtopics

A3 Databases4 subtopics

A4 Machine learning4 subtopics

B1 Computational thinking1 subtopic

B2 Programming5 subtopics

B3 Object-oriented programming2 subtopics

B4 Abstract data types (HL only)1 subtopic

Commonly Used Design Patterns in OOP

What Are Design Patterns?

Key Patterns in the IB Syllabus

Singleton Pattern

anim nostrud sit dolore minim proident quis fugiat velit et eiusmod nulla quis nulla mollit dolor sunt culpa aliqua

Duis aute irure dolor in reprehenderit

Excepteur sint occaecat cupidatat non proident

Unlock the rest of this chapter with a free account

Commonly Used Design Patterns in OOP

What Are Design Patterns?

Key Patterns in the IB Syllabus

Singleton Pattern

anim nostrud sit dolore minim proident quis fugiat velit et eiusmod nulla quis nulla mollit dolor sunt culpa aliqua

Duis aute irure dolor in reprehenderit

Excepteur sint occaecat cupidatat non proident

Unlock the rest of this chapter with a free account