Module java.base

Package java.util.function

Interface DoubleUnaryOperator

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 DoubleUnaryOperator

Represents an operation on a single double-valued operand that produces a double-valued result. This is the primitive type specialization of UnaryOperator for double.

This is a functional interface whose functional method is applyAsDouble(double).

Since:

1.8

See Also:

• UnaryOperator

Method Summary

Modifier and Type	Method	Description
default 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.
double	applyAsDouble(double operand)	Applies this operator to the given operand.
default 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	identity()	Returns a unary operator that always returns its input argument.

Method Details

applyAsDouble

double applyAsDouble(double operand)

Applies this operator to the given operand.

Parameters:

operand - the operand

Returns:

the operator result

compose

default 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. If evaluation of either operator throws an exception, it is relayed to the caller of the composed operator.

Parameters:

before - the operator to apply before this operator is applied

Returns:

a composed operator that first applies the before operator and then applies this operator

Throws:

NullPointerException - if before is null

See Also:

• andThen(DoubleUnaryOperator)

andThen

default 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. If evaluation of either operator throws an exception, it is relayed to the caller of the composed operator.

Parameters:

after - the operator to apply after this operator is applied

Returns:

a composed operator that first applies this operator and then applies the after operator

Throws:

NullPointerException - if after is null

See Also:

• compose(DoubleUnaryOperator)

identity

static DoubleUnaryOperator identity()

Returns a unary operator that always returns its input argument.

Returns:

a unary operator that always returns its input argument