Recap

You now have a solid understanding of the basics of Kotlin. Before we explore ways to continue your Kotlin journey, let’s briefly recap all that you learned in this course. After all, repetition is one of the keys to learning.

Variables and Mutable Types #

• Kotlin favors the use of read-only variables.
  • Use val to create a read-only variable.
  • Use var to create a mutable variable.
  • First, note how declaring a read-only variable takes no more characters than a mutable one, in contrast to many other languages (e.g., Java requiring the final modifier).
  • Second, note that variable names in your code are usually nicely aligned because the two keywords have the same number of characters.
• In alignment with this, Kotlin also differentiates between read-only and mutable collection types, again favoring the use of read-only ones.
  • For instance, a simple listOf(...) will give you a read-only list.
  • To get a mutable list, you have to explicitly write mutableListOf(...), making read-only the default case.

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