Uses of Interface java.util.function.ToDoubleFunction (Java SE 11 & JDK 11 )

Packages that use ToDoubleFunction
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 ToDoubleFunction in java.util

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

Uses of ToDoubleFunction in java.util.concurrent

Methods in java.util.concurrent with parameters of type ToDoubleFunction
Modifier and Type	Method	Description
`double`	ConcurrentHashMap.`reduceEntriesToDouble(long parallelismThreshold, ToDoubleFunction<Map.Entry<K,V>> transformer, double basis, DoubleBinaryOperator reducer)`	Returns the result of accumulating the given transformation of all entries using the given reducer to combine values, and the given basis as an identity value.
`double`	ConcurrentHashMap.`reduceKeysToDouble(long parallelismThreshold, ToDoubleFunction<? super K> transformer, double basis, DoubleBinaryOperator reducer)`	Returns the result of accumulating the given transformation of all keys using the given reducer to combine values, and the given basis as an identity value.
`double`	ConcurrentHashMap.`reduceValuesToDouble(long parallelismThreshold, ToDoubleFunction<? super V> transformer, double basis, DoubleBinaryOperator reducer)`	Returns the result of accumulating the given transformation of all values using the given reducer to combine values, and the given basis as an identity value.

Uses of ToDoubleFunction in java.util.stream

Methods in java.util.stream with parameters of type ToDoubleFunction
Modifier and Type	Method	Description
`static <T> Collector<T,?,Double>`	Collectors.`averagingDouble(ToDoubleFunction<? super T> mapper)`	Returns a `Collector` that produces the arithmetic mean of a double-valued function applied to the input elements.
`DoubleStream`	Stream.`mapToDouble(ToDoubleFunction<? super T> mapper)`	Returns a `DoubleStream` consisting of the results of applying the given function to the elements of this stream.
`static <T> Collector<T,?,DoubleSummaryStatistics>`	Collectors.`summarizingDouble(ToDoubleFunction<? super T> mapper)`	Returns a `Collector` which applies an `double`-producing mapping function to each input element, and returns summary statistics for the resulting values.
`static <T> Collector<T,?,Double>`	Collectors.`summingDouble(ToDoubleFunction<? super T> mapper)`	Returns a `Collector` that produces the sum of a double-valued function applied to the input elements.