Kotlin Standard Library

The Kotlin Standard Library provides living essentials for everyday work with Kotlin. These include:

  • Higher-order functions implementing idiomatic patterns (let, apply, use, synchronized, etc).
  • Extension functions providing querying operations for collections (eager) and sequences (lazy).
  • Various utilities for working with strings and char sequences.
  • Extensions for JDK classes making it convenient to work with files, IO, and threading.

Packages

kotlin

Core functions and types, available on all supported platforms.

kotlin.annotation

Library support for the Kotlin annotation facility.

kotlin.collections

Collection types, such as Iterable, Collection, List, Set, Map and related top-level and extension functions.

kotlin.comparisons

Helper functions for creating Comparator instances.

kotlin.concurrent

Utility functions for concurrent programming.

kotlin.io

IO API for working with files and streams.

kotlin.jvm

Functions and annotations specific to the Java platform.

kotlin.properties

Standard implementations of delegates for delegated properties and helper functions for implementing custom delegates.

kotlin.ranges

Ranges, Progressions and related top-level and extension functions.

kotlin.reflect

Runtime API for Kotlin reflection

kotlin.reflect.jvm

Runtime API for interoperability between Kotlin reflection and Java reflection.

kotlin.sequences

Sequence type that represents lazily evaluated collections. Top-level functions for instantiating sequences and extension functions for sequences.

kotlin.system

System-related utility functions.

kotlin.text

Functions for working with text and regular expressions.

Index

All Types