Uses of Interface java.util.function.ToIntFunction (Java SE 26 & JDK 26)
Description: use: module: java.base, package: java.util.function, interface: ToIntFunction

# Uses of Interface
java.util.function.ToIntFunction

Packages that use ToIntFunction
Package
Description
java.util
Contains the collections framework, some internationalization support classes, a service loader, properties, random number generation, string parsing and scanning classes, base64 encoding and decoding, a bit array, and several miscellaneous utility classes.
java.util.concurrent
Utility classes commonly useful in concurrent programming.
java.util.stream
Classes to support functional-style operations on streams of elements, such as map-reduce transformations on collections.

- ## Uses of ToIntFunction in java.util

  Methods in java.util with parameters of type ToIntFunction
  Modifier and Type
  Method
  Description
  `static <T> Comparator<T>`
  Comparator.`comparingInt(ToIntFunction<? super T> keyExtractor)`
  Accepts a function that extracts an `int` sort key from a type `T`, and returns a `Comparator<T>` that compares by that sort key.
  `default Comparator<T>`
  Comparator.`thenComparingInt(ToIntFunction<? super T> keyExtractor)`
  Returns a lexicographic-order comparator with a function that extracts an `int` sort key.

- ## Uses of ToIntFunction in java.util.concurrent

  Methods in java.util.concurrent with parameters of type ToIntFunction
  Modifier and Type
  Method
  Description
  `int`
  ConcurrentHashMap.`reduceEntriesToInt(long parallelismThreshold, ToIntFunction<Map.Entry<K,V>> transformer, int basis, IntBinaryOperator reducer)`
  Returns the result of bulk accumulating the given transformation of all entries using the given reducer to combine values, and the given basis as an identity value.
  `int`
  ConcurrentHashMap.`reduceKeysToInt(long parallelismThreshold, ToIntFunction<? super K> transformer, int basis, IntBinaryOperator reducer)`
  Returns the result of bulk accumulating the given transformation of all keys using the given reducer to combine values, and the given basis as an identity value.
  `int`
  ConcurrentHashMap.`reduceValuesToInt(long parallelismThreshold, ToIntFunction<? super V> transformer, int basis, IntBinaryOperator reducer)`
  Returns the result of bulk accumulating the given transformation of all values using the given reducer to combine values, and the given basis as an identity value.

- ## Uses of ToIntFunction in java.util.stream

  Methods in java.util.stream with parameters of type ToIntFunction
  Modifier and Type
  Method
  Description
  `static <T> Collector<T,?,Double>`
  Collectors.`averagingInt(ToIntFunction<? super T> mapper)`
  Returns a `Collector` that produces the arithmetic mean of an integer-valued function applied to the input elements.
  `IntStream`
  Stream.`mapToInt(ToIntFunction<? super T> mapper)`
  Returns an `IntStream` consisting of the results of applying the given function to the elements of this stream.
  `static <T> Collector<T, ?, IntSummaryStatistics>`
  Collectors.`summarizingInt(ToIntFunction<? super T> mapper)`
  Returns a `Collector` which applies an `int`-producing mapping function to each input element, and returns summary statistics for the resulting values.
  `static <T> Collector<T,?,Integer>`
  Collectors.`summingInt(ToIntFunction<? super T> mapper)`
  Returns a `Collector` that produces the sum of an integer-valued function applied to the input elements.