Strategy Design Pattern

lets the algorithm vary independently from clients that use it

When to use it?

• When you want to define a class that will have one behavior that is similar to other behavior in the list.

• When you need to use one of the several behaviors dynamically

Identify the aspects of your application that vary and separate them from what stays the same.

Pros ( 👍) & Cons ( 👎)

• 👍 Often reduces the long list of conditionals
• 👍 Reduce duplicate code
• 👍 Keeps class changes from forcing other class changes
• 👍 can hide complicated/secret code from the user
• 👍You can replace inheritance with composition.

• 👎 Increased number of objects and classes
• 👎A lot of modern programming languages have functional-type support that lets you implement different versions of an algorithm inside a set of anonymous functions. Then you could use these functions exactly as you’d have used the strategy objects, but without bloating your code with extra classes and interfaces.

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The Strategy pattern can be implemented with a simple anonymous (lambda) function in most modern programming languages.

Code

Strategy Design Pattern

References

• https://www.newthinktank.com/2012/08/strategy-design-pattern-tutorial/

• https://refactoring.guru/design-patterns/strategy

• https://sourcemaking.com/design_patterns/strategy