Advanced JavaScript Design Patterns

What are Design Patterns?

Design patterns are proven and robust solutions for addressing common problems in software design and other contexts related to interaction and interfaces. These techniques provide structured and effective approaches to solving recurring challenges, promoting efficiency, reusability, and clarity in software development.

Table of Content

1. Creational Patterns (Object Creation)

These patterns focus on object instantiation while maintaining flexibility and efficiency.

• Abstract Factory → Creates families of related objects without specifying their concrete classes.
• Builder → Constructs complex objects step-by-step for better readability and flexibility.
• Factory Method → Defines an interface for object creation, allowing subclasses to determine the actual implementation.
• Prototype → Creates new objects by copying an existing instance (useful for expensive object creation).
• Singleton → Ensures only one instance of a class exists globally.

2. Structural Patterns (Class & Object Composition)

These patterns simplify the design by organizing object relationships efficiently.

• Adapter (Composition & Inheritance) → Converts one interface to another to enable compatibility.
• Bridge → Decouples abstraction from implementation, allowing independent modifications.
• Composite → Treats individual objects and groups of objects uniformly (tree structure).
• Decorator → Dynamically adds new behavior to objects without altering existing code.
• Facade → Provides a simple interface for complex subsystems.
• Flyweight → Reduces memory usage by sharing common object instances.
• Proxy → Controls access to an object, often used for security or performance optimizations.

3. Behavioral Patterns (Object Interaction)

These patterns focus on communication between objects and define workflows.

• Chain of Responsibility → Passes a request along a chain of handlers until one handles it.
• Command → Encapsulates requests as objects, enabling undo/redo functionality.
• Interpreter → Defines a language grammar and an interpreter to process expressions.
• Iterator → Provides a way to sequentially access elements without exposing the underlying structure.
• Mediator → Centralizes communication between objects to reduce dependencies.
• Memento → Captures an object’s state to restore it later (useful for undo mechanisms).
• Observer → Establishes a one-to-many dependency where observers get notified of state changes.
• State → Allows an object to change its behavior when its state changes.
• Strategy → Defines interchangeable algorithms that can be selected dynamically.
• Template Method → Defines a skeleton for an algorithm, allowing subclasses to modify specific steps.
• Visitor → Adds new operations to an object structure without modifying its classes.