open fun in kotlin

The "open" keyword in Kotlin is used to declare a member (function, property, or class) that can be overridden in a subclass. It allows subclasses to provide their own implementation of the member.

The "fun" keyword in Kotlin is used to declare a function. It is followed by the function name and the parameters it takes, if any. In Kotlin, all functions are public by default unless specified otherwise.

When you combine both keywords, "open fun", you are declaring a function that can be overridden in a subclass.

Here are the explanations for each step:

1. First, you use the "open" keyword to declare that the function can be overridden.
2. Then, you use the "fun" keyword to declare that you are defining a function.
3. After the "fun" keyword, you specify the name of the function.
4. Next, you can specify the parameters that the function takes, if any, within parentheses.
5. Following the parameters, you can specify the return type of the function after a colon (:).
6. Finally, you define the body of the function within curly braces ({}) and write the code that should be executed when the function is called.

By using the "open fun" combination, you are allowing subclasses to provide their own implementation of the function, giving them the flexibility to customize the behavior of the function according to their specific needs.