Strategy Design Pattern Example

Strategy Design Pattern: Strategy pattern defines family of algorithms which are encapsulated and are interchangeable at run time depending on a factor that requires a particular algorithm to be executed. Strategy pattern encourages open-close design principle where a class is open for extension but closed for modification.

It is a suitable replacement for a if-else or switch-case statements or complex conditional logic within a method. It also leads to more testable code, especially when coupled with IOC.

When to use: Let us assume that you are a Telecom service provider and you provide prepaid recharge facility to the customer. Depending on the recharge amount you would like to provide free SMS and free Talk time offer.

The Telecom service system can have a TelecomOperator class. On each recharge this class has to determine different offer depending on the recharge amount....

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