stdlib
1.6
1.8
1.7
1.6
1.5
1.4
1.3
1.2
1.1
1.0
Common
stdlib
/
kotlin.collections
/
ArrayDeque
/
firstOrNull
first
Or
Null
fun
firstOrNull
(
)
:
E
?
(
source
)
Returns the first element, or
null
if this deque is empty.
Since Kotlin
1.2