Strategy Design Pattern Explained

Strategy defines a family of interchangeable algorithms, encapsulating each one and letting the algorithm vary independently from the code that uses it.

Why it exists

• Some behavior needs to vary at runtime — like different sorting or pricing rules — without littering the calling code with conditionals for every variant

How to apply it

• Define a common interface for the interchangeable behavior, then implement each variant as its own class conforming to it
• The calling code holds a reference to the interface and can swap the concrete strategy at runtime

FAQ

How is Strategy different from just using if/else?

Strategy moves each variant into its own class behind a shared interface, so adding a new variant means adding a new class rather than editing a growing conditional.