In the adapter design pattern, what is the main purpose?

• A. To rename variables
• B. To allow incompatible interfaces to work together by wrapping an adapter
• C. To optimize runtime performance
• D. To manage memory usage

Answer: (B)

The primary goal of the adapter pattern is to let two incompatible interfaces work together by wrapping one in another. It acts as a translator that takes calls from a client expecting a certain interface and converts them into a form that another component can understand, without changing either side. For example, if you have code that interacts with a standard Logger interface but you want to use a logging library with a different API, an adapter can implement the standard Logger interface and internally translate those calls to the new library. This keeps the rest of the system unchanged while enabling the new component to be used.

Renaming variables is a refactoring task, not the purpose of this pattern. Optimizing runtime performance relates to making code run faster, not to compatibility between interfaces. Memory management concerns arise from how objects are allocated and freed, which isn’t the adapter’s aim.