The -> is a separator. It is special symbol used to separate code with different purposes. It can be used to: Separate the parameters and body of a lambda expression val sum = { x: Int, y: Int -> x + y } Separate the parameters and return type declaration in a function type (R, T) -> R.

What does Kotlin mean?

The -> is a separator. It is special symbol used to separate code with different purposes. It can be used to: Separate the parameters and body of a lambda expression val sum = { x: Int, y: Int -> x + y } Separate the parameters and return type declaration in a function type (R, T) -> R.

What does += mean in Kotlin?

The strange += operator in Kotlin introduce an immutable structure of the class for the plus operator which means any class outside the class can’t edit its internal data. introduce a mutable structure of the class for the plusAssign operator which means its internal data can be edited anywhere.