kotlin-stdlib/kotlin.collections/AbstractMutableList/add

add

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

Inserts an element into the list at the specified index.

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
expect open override fun add(element: E): Boolean(source)

Adds the specified element to the end of this list.

Since Kotlin

1.1

Return

true because the list is always modified as the result of this operation.