Strategy Pattern

Kind: pattern

Layer: Design Patterns Core

Aliases: Policy Pattern

Record: architecture:strategy-pattern

Severity: recommended

Scope: algorithm, policy, behavior

Canonical: Ontology

A design pattern that puts each interchangeable algorithm behind one interface, so the caller selects behavior by passing an object.

Listed in Architecture principles, after Dashboards and before Template Method Pattern.

Requires

• Interchangeable Algorithms

Reinforces

• Open/Closed Principle (OCP)
• Polymorphism

Enables

• Runtime Behavior Selection

Conflicts with

• Large Conditional Logic

In tension with

• Class Count

Tensions

• Strategy Pattern / Class Count

Violated by

• Large Conditional Logic

Severity

• recommended

Category

• Behavioral Patterns

Refactors

• Dynamic Binding
• Dynamic Dispatch
• Composition Over Inheritance

Enabled by

• Composition Over Inheritance

Linked from

• Runtime Discovery / Dynamic Binding
• Core Modular Design
• SOLID / Object-Oriented Design
• Behavioral Patterns
• Severity levels
• The resolutions