kotlin-stdlib / kotlin.sequences / count count Common JVM JS Native 1.0 fun < T > Sequence < T > . count ( ) : Int (source) Returns the number of elements in this sequence. The operation is terminal . Common JVM JS Native 1.0 inline fun < T > Sequence < T > . count ( predicate : ( T ) -> Boolean ) : Int (source) Returns the number of elements matching the given predicate . The operation is terminal .