WBF Academy
Functional Intermediate 3 min read

Extension Functions: Add Behaviour Without Inheritance

Extend any class — even ones you don't own

Android Academy

Android Academy

Android Engineer

1 year ago

Extension functions let you add methods to existing classes without subclassing or modifying them. They are resolved statically at compile time, so they don't actually modify the class. Common Android patterns include adding show()/hide() helpers to View, or isEmailValid() to String. Group related extensions in a dedicated file (e.g., ViewExtensions.kt) for discoverability.

#kotlin #extension-functions #android