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 Detail

    - #### 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