Uses of Interface java.util.function.DoubleUnaryOperator (Java Platform SE 8 )
Date: 2026-04-17

## Uses of Interface
java.util.function.DoubleUnaryOperator

- Packages that use DoubleUnaryOperator
  Package | Description
  --- | ---
  java.util.function | Functional interfaces provide target types for lambda expressions and method references.
  java.util.stream | Classes to support functional-style operations on streams of elements, such as map-reduce transformations on collections.

- - ### Uses of DoubleUnaryOperator in java.util.function

    Methods in java.util.function that return DoubleUnaryOperator
    Modifier and Type | Method and Description
    --- | ---
    `default DoubleUnaryOperator` | DoubleUnaryOperator.`andThen(DoubleUnaryOperator after)` Returns a composed operator that first applies this operator to its input, and then applies the `after` operator to the result.
    `default DoubleUnaryOperator` | DoubleUnaryOperator.`compose(DoubleUnaryOperator before)` Returns a composed operator that first applies the `before` operator to its input, and then applies this operator to the result.
    `static DoubleUnaryOperator` | DoubleUnaryOperator.`identity()` Returns a unary operator that always returns its input argument.

    Methods in java.util.function with parameters of type DoubleUnaryOperator
    Modifier and Type | Method and Description
    --- | ---
    `default DoubleUnaryOperator` | DoubleUnaryOperator.`andThen(DoubleUnaryOperator after)` Returns a composed operator that first applies this operator to its input, and then applies the `after` operator to the result.
    `default DoubleUnaryOperator` | DoubleUnaryOperator.`compose(DoubleUnaryOperator before)` Returns a composed operator that first applies the `before` operator to its input, and then applies this operator to the result.

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

    Methods in java.util.stream with parameters of type DoubleUnaryOperator
    Modifier and Type | Method and Description
    --- | ---
    `static DoubleStream` | DoubleStream.`iterate(double seed, DoubleUnaryOperator f)` Returns an infinite sequential ordered `DoubleStream` produced by iterative application of a function `f` to an initial element `seed`, producing a `Stream` consisting of `seed`, `f(seed)`, `f(f(seed))`, etc.
    `DoubleStream` | DoubleStream.`map(DoubleUnaryOperator mapper)` Returns a stream consisting of the results of applying the given function to the elements of this stream.

Submit a bug or feature
For further API reference and developer documentation, see Java SE Documentation. That documentation contains more detailed, developer-targeted descriptions, with conceptual overviews, definitions of terms, workarounds, and working code examples.
Copyright © 1993, 2026, Oracle and/or its affiliates. All rights reserved. Use is subject to license terms. Also see the documentation redistribution policy.