kotlin-stdlib/kotlin.collections/AbstractMutableList/set

set

abstract operator override fun set(index: Int, element: E): E(source)

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.

Since Kotlin

1.1

Return

the element previously at the specified position.