Platform and version requirements: JVM (1.0), JS (1.1), Native (1.3)

abstract fun set(index: Int, element: E): E

For JVM

Replaces the element at the specified position in this list with the specified element.

This method is redeclared as abstract, because it's not implemented in the base class, so it must be always overridden in the concrete mutable collection implementation.

Return the element previously at the specified position.

For JS, Native

Replaces the element at the specified position in this list with the specified element.

Return the element previously at the specified position.