UnaryOperator (Java SE 15 & JDK 15)
Description: declaration: module: java.base, package: java.util.function, interface: UnaryOperator
Keywords: java.util.function.UnaryOperator interface

Module java.base
Package java.util.function

# Interface UnaryOperator<T>

Type Parameters:
  `T` - the type of the operand and result of the operator

All Superinterfaces:
  `Function<T,​T>`

Functional Interface:
  This is a functional interface and can therefore be used as the assignment target for a lambda expression or method reference.

    @FunctionalInterface
    public interface UnaryOperator<T>
    extends Function<T,​T>

Represents an operation on a single operand that produces a result of the same type as its operand. This is a specialization of `Function` for the case where the operand and result are of the same type.

This is a functional interface whose functional method is `Function.apply(Object)`.

Since:
  1.8
See Also:
  `Function`

- ## Method Summary

  Static Methods
  Modifier and Type | Method | Description
  --- | --- | ---
  `static <T> UnaryOperator<T>` | `identity()` | Returns a unary operator that always returns its input argument.

  ### Methods declared in interface java.util.function.Function

  `andThen, apply, compose`

- ## Method Details

  - ### identity

    static <T> UnaryOperator<T> identity()
    Returns a unary operator that always returns its input argument.
    Type Parameters:
      `T` - the type of the input and output of the operator
    Returns:
      a unary operator that always returns its input argument