Operators are functions that use a symbolic name. In Kotlin, many built-in operators are actually function calls. For example, array access is a real function:
val array = arrayOf(1, 2, 3)
val element = array[0]
In this example, the [0] operation is translated into a call to the function get(index: Int) defined on the Array class.
Many operators are predefined in Kotlin, just like they are in most other languages, and most operators tend to be combined with the infix style. This is immediately familiar in the guise of binary operators on numbers.
Note
Although Kotlin treats operations on basic types as functions, they are compiled to the appropriate byte code operations to avoid function overhead and ensure maximum performance.
Often operators are preferred over real names if the operators are already familiar to the users. In fields such as mathematics or physics, where operators are routinely used, it would be natural to also use operations in code where appropriate...