Kotlin provides rich API for working with collections. Understanding functions like map, filter, reduce, flatMap etc. can help you to manipulate collections efficiently.

Kotlin’s type alias feature introduces a new name for any existing type which can help to shorten longer type references and improve readability.

Sealed classes are used for representing restricted class hierarchies. When a value is of a type of sealed class, we know it can only be of one of the subclasses. This is very helpful in when expressions, and it increases the safety and predictability of your code.

Coroutines are a great feature of Kotlin that make asynchronous programming much more straightforward and readable by replacing callbacks and simplifying code.

Kotlin allows you to extend a class with new functionality without having to inherit from the class, through the use of extension functions. It helps in writing cleaner and more readable code.

Immutable objects make your code safer and more predictable. Unless you need to change a variable, always declare it as val instead of var.

In Kotlin, you can create data classes using the data keyword, which automatically generates essential methods like equals(), hashCode(), toString(), and copy methods.

In Kotlin, when is a more powerful version of the switch-case statement found in languages like Java. It can handle multiple types and allows for more expressive and concise code.

Kotlin has robust null safety built right into its type system. Take advantage of it to avoid null pointer exceptions. For example, instead of using a normal type like String, use String? if the string can be null.

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