Extension Functions
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What is Extension Functions?
Extension functions in Kotlin provide a way to add new functions to existing classes without inheriting from them or using any type of design pattern such as Decorator. This is achieved by defining a function that can be called as if it were a member of the class, even though it's defined outside of it. Extension functions are resolved statically, meaning the function call is determined by the declared type of the receiver, not its runtime type.
Free resources to learn Extension Functions
- Official docsExtension functions
Extension Functions: common questions
Can I learn Extension Functions in Hindi?
This lesson is written in English. Once you sign in, open it in the interactive course and ask the AI tutor to explain Extension Functions in Hindi or Hinglish. The tutor answers from this lesson’s own text, so it stays on the syllabus, and it runs on your own Google, OpenAI or Anthropic key.
Is this Extension Functions tutorial for beginners?
It is lesson 55 of 153 in the free Kotlin roadmap, in stage 20, Extension Functions. If you are new to Kotlin, start from stage 1 and come back here in order; if you already know the earlier stages, this lesson stands on its own.