# Class DoubleExpression

java.lang.Object
javafx.beans.binding.NumberExpressionBase
javafx.beans.binding.DoubleExpression

All Implemented Interfaces:
  `NumberExpression, Observable, ObservableDoubleValue, ObservableNumberValue, ObservableValue<Number>`

Direct Known Subclasses:
  `DoubleBinding, ReadOnlyDoubleProperty`

public abstract class DoubleExpression extends NumberExpressionBase implements ObservableDoubleValue
`DoubleExpression` is an `ObservableDoubleValue` plus additional convenience methods to generate bindings in a fluent style.

A concrete sub-class of `DoubleExpression` has to implement the method `ObservableDoubleValue.get()`, which provides the actual value of this expression.

Since:
  JavaFX 2.0

- ## Constructor Summary

  Constructors
  Constructor
  Description
  `DoubleExpression()`
  Creates a default `DoubleExpression`.

- ## Method Summary

  Modifier and Type
  Method
  Description
  `DoubleBinding`
  `add(double other)`
  Creates a new `NumberBinding` that calculates the sum of this `NumberExpression` and a constant value.
  `DoubleBinding`
  `add(float other)`
  Creates a new `NumberBinding` that calculates the sum of this `NumberExpression` and a constant value.
  `DoubleBinding`
  `add(int other)`
  Creates a new `NumberBinding` that calculates the sum of this `NumberExpression` and a constant value.
  `DoubleBinding`
  `add(long other)`
  Creates a new `NumberBinding` that calculates the sum of this `NumberExpression` and a constant value.
  `DoubleBinding`
  `add(ObservableNumberValue other)`
  Creates a new `NumberBinding` that calculates the sum of this `NumberExpression` and another `ObservableNumberValue`.
  `ObjectExpression<Double>`
  `asObject()`
  Creates an `ObjectExpression` that holds the value of this `DoubleExpression`.
  `DoubleBinding`
  `divide(double other)`
  Creates a new `NumberBinding` that calculates the division of this `NumberExpression` and a constant value.
  `DoubleBinding`
  `divide(float other)`
  Creates a new `NumberBinding` that calculates the division of this `NumberExpression` and a constant value.
  `DoubleBinding`
  `divide(int other)`
  Creates a new `NumberBinding` that calculates the division of this `NumberExpression` and a constant value.
  `DoubleBinding`
  `divide(long other)`
  Creates a new `NumberBinding` that calculates the division of this `NumberExpression` and a constant value.
  `DoubleBinding`
  `divide(ObservableNumberValue other)`
  Creates a new `NumberBinding` that calculates the division of this `NumberExpression` and another `ObservableNumberValue`.
  `static DoubleExpression`
  `doubleExpression(ObservableDoubleValue value)`
  Returns a `DoubleExpression` that wraps a `ObservableDoubleValue`.
  `static <T extends Number>
  DoubleExpression`
  `doubleExpression(ObservableValue<T> value)`
  Returns a `DoubleExpression` that wraps an `ObservableValue`.
  `double`
  `doubleValue()`
  Returns the value of this `ObservableNumberValue` as a `double`.
  `float`
  `floatValue()`
  Returns the value of this `ObservableNumberValue` as a `float`.
  `Double`
  `getValue()`
  Returns the current value of this `ObservableValue`
  `int`
  `intValue()`
  Returns the value of this `ObservableNumberValue` as an `int` .
  `long`
  `longValue()`
  Returns the value of this `ObservableNumberValue` as a `long` .
  `DoubleBinding`
  `multiply(double other)`
  Creates a new `NumberBinding` that calculates the product of this `NumberExpression` and a constant value.
  `DoubleBinding`
  `multiply(float other)`
  Creates a new `NumberBinding` that calculates the product of this `NumberExpression` and a constant value.
  `DoubleBinding`
  `multiply(int other)`
  Creates a new `NumberBinding` that calculates the product of this `NumberExpression` and a constant value.
  `DoubleBinding`
  `multiply(long other)`
  Creates a new `NumberBinding` that calculates the product of this `NumberExpression` and a constant value.
  `DoubleBinding`
  `multiply(ObservableNumberValue other)`
  Creates a new `NumberBinding` that calculates the product of this `NumberExpression` and another `ObservableNumberValue`.
  `DoubleBinding`
  `negate()`
  Creates a new `NumberBinding` that calculates the negation of `NumberExpression`.
  `DoubleBinding`
  `subtract(double other)`
  Creates a new `NumberBinding` that calculates the difference of this `NumberExpression` and a constant value.
  `DoubleBinding`
  `subtract(float other)`
  Creates a new `NumberBinding` that calculates the difference of this `NumberExpression` and a constant value.
  `DoubleBinding`
  `subtract(int other)`
  Creates a new `NumberBinding` that calculates the difference of this `NumberExpression` and a constant value.
  `DoubleBinding`
  `subtract(long other)`
  Creates a new `NumberBinding` that calculates the difference of this `NumberExpression` and a constant value.
  `DoubleBinding`
  `subtract(ObservableNumberValue other)`
  Creates a new `NumberBinding` that calculates the difference of this `NumberExpression` and another `ObservableNumberValue`.

  ### Methods declared in class NumberExpressionBase

  `asString, asString, asString, greaterThan, greaterThan, greaterThan, greaterThan, greaterThan, greaterThanOrEqualTo, greaterThanOrEqualTo, greaterThanOrEqualTo, greaterThanOrEqualTo, greaterThanOrEqualTo, isEqualTo, isEqualTo, isEqualTo, isEqualTo, isEqualTo, isEqualTo, isEqualTo, isEqualTo, isNotEqualTo, isNotEqualTo, isNotEqualTo, isNotEqualTo, isNotEqualTo, isNotEqualTo, isNotEqualTo, isNotEqualTo, lessThan, lessThan, lessThan, lessThan, lessThan, lessThanOrEqualTo, lessThanOrEqualTo, lessThanOrEqualTo, lessThanOrEqualTo, lessThanOrEqualTo, numberExpression`

  ### Methods declared in class Object

  `clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

  ### Methods declared in interface Observable

  `addListener, removeListener, subscribe`

  ### Methods declared in interface ObservableDoubleValue

  `get`

  ### Methods declared in interface ObservableValue

  `addListener, flatMap, map, orElse, removeListener, subscribe, subscribe, when`

- ## Constructor Details

  - ### DoubleExpression

    public DoubleExpression()
    Creates a default `DoubleExpression`.

- ## Method Details

  - ### intValue

    public int intValue()
    Description copied from interface: `ObservableNumberValue`
    Returns the value of this `ObservableNumberValue` as an `int` . If the value is not an `int`, a standard cast is performed.
    Specified by:
      `intValue` in interface `ObservableNumberValue`
    Returns:
      The value of this `ObservableNumberValue` as an `int`

  - ### longValue

    public long longValue()
    Description copied from interface: `ObservableNumberValue`
    Returns the value of this `ObservableNumberValue` as a `long` . If the value is not a `long`, a standard cast is performed.
    Specified by:
      `longValue` in interface `ObservableNumberValue`
    Returns:
      The value of this `ObservableNumberValue` as a `long`

  - ### floatValue

    public float floatValue()
    Description copied from interface: `ObservableNumberValue`
    Returns the value of this `ObservableNumberValue` as a `float`. If the value is not a `float`, a standard cast is performed.
    Specified by:
      `floatValue` in interface `ObservableNumberValue`
    Returns:
      The value of this `ObservableNumberValue` as a `float`

  - ### doubleValue

    public double doubleValue()
    Description copied from interface: `ObservableNumberValue`
    Returns the value of this `ObservableNumberValue` as a `double`. If the value is not a `double`, a standard cast is performed.
    Specified by:
      `doubleValue` in interface `ObservableNumberValue`
    Returns:
      The value of this `ObservableNumberValue` as a `double`

  - ### getValue

    public Double getValue()
    Description copied from interface: `ObservableValue`
    Returns the current value of this `ObservableValue`
    Specified by:
      `getValue` in interface `ObservableValue<Number>`
    Returns:
      The current value

  - ### doubleExpression

    public static DoubleExpression doubleExpression(ObservableDoubleValue value)
    Returns a `DoubleExpression` that wraps a `ObservableDoubleValue`. If the `ObservableDoubleValue` is already a `DoubleExpression`, it will be returned. Otherwise a new `DoubleBinding` is created that is bound to the `ObservableDoubleValue`.
    Parameters:
      `value` - The source `ObservableDoubleValue`
    Returns:
      A `DoubleExpression` that wraps the `ObservableDoubleValue` if necessary
    Throws:
      `NullPointerException` - if `value` is `null`

  - ### doubleExpression

    public static <T extends Number> DoubleExpression doubleExpression(ObservableValue<T> value)
    Returns a `DoubleExpression` that wraps an `ObservableValue`. If the `ObservableValue` is already a `DoubleExpression`, it will be returned. Otherwise a new `DoubleBinding` is created that is bound to the `ObservableValue`.

    Note: this method can be used to convert an `ObjectExpression` or `ObjectProperty` of specific number type to DoubleExpression, which is essentially an `ObservableValue<Number>`. See sample below.

    >       DoubleProperty doubleProperty = new SimpleDoubleProperty(1.0);
    >       ObjectProperty<Double> objectProperty = new SimpleObjectProperty<>(2.0);
    >       BooleanBinding binding = doubleProperty.greaterThan(DoubleExpression.doubleExpression(objectProperty));

    Note: null values will be interpreted as 0.0
    Type Parameters:
      `T` - The type of Number to be wrapped
    Parameters:
      `value` - The source `ObservableValue`
    Returns:
      A `DoubleExpression` that wraps the `ObservableValue` if necessary
    Throws:
      `NullPointerException` - if `value` is `null`
    Since:
      JavaFX 8.0

  - ### negate

    public DoubleBinding negate()
    Description copied from interface: `NumberExpression`
    Creates a new `NumberBinding` that calculates the negation of `NumberExpression`.
    Specified by:
      `negate` in interface `NumberExpression`
    Returns:
      the new `NumberBinding`

  - ### add

    public DoubleBinding add(ObservableNumberValue other)
    Description copied from interface: `NumberExpression`
    Creates a new `NumberBinding` that calculates the sum of this `NumberExpression` and another `ObservableNumberValue`.
    Specified by:
      `add` in interface `NumberExpression`
    Parameters:
      `other` - the second `ObservableNumberValue`
    Returns:
      the new `NumberBinding`

  - ### add

    public DoubleBinding add(double other)
    Description copied from interface: `NumberExpression`
    Creates a new `NumberBinding` that calculates the sum of this `NumberExpression` and a constant value.
    Specified by:
      `add` in interface `NumberExpression`
    Parameters:
      `other` - the constant value
    Returns:
      the new `NumberBinding`

  - ### add

    public DoubleBinding add(float other)
    Description copied from interface: `NumberExpression`
    Creates a new `NumberBinding` that calculates the sum of this `NumberExpression` and a constant value.
    Specified by:
      `add` in interface `NumberExpression`
    Parameters:
      `other` - the constant value
    Returns:
      the new `NumberBinding`

  - ### add

    public DoubleBinding add(long other)
    Description copied from interface: `NumberExpression`
    Creates a new `NumberBinding` that calculates the sum of this `NumberExpression` and a constant value.
    Specified by:
      `add` in interface `NumberExpression`
    Parameters:
      `other` - the constant value
    Returns:
      the new `NumberBinding`

  - ### add

    public DoubleBinding add(int other)
    Description copied from interface: `NumberExpression`
    Creates a new `NumberBinding` that calculates the sum of this `NumberExpression` and a constant value.
    Specified by:
      `add` in interface `NumberExpression`
    Parameters:
      `other` - the constant value
    Returns:
      the new `NumberBinding`

  - ### subtract

    public DoubleBinding subtract(ObservableNumberValue other)
    Description copied from interface: `NumberExpression`
    Creates a new `NumberBinding` that calculates the difference of this `NumberExpression` and another `ObservableNumberValue`.
    Specified by:
      `subtract` in interface `NumberExpression`
    Parameters:
      `other` - the second `ObservableNumberValue`
    Returns:
      the new `NumberBinding`

  - ### subtract

    public DoubleBinding subtract(double other)
    Description copied from interface: `NumberExpression`
    Creates a new `NumberBinding` that calculates the difference of this `NumberExpression` and a constant value.
    Specified by:
      `subtract` in interface `NumberExpression`
    Parameters:
      `other` - the constant value
    Returns:
      the new `NumberBinding`

  - ### subtract

    public DoubleBinding subtract(float other)
    Description copied from interface: `NumberExpression`
    Creates a new `NumberBinding` that calculates the difference of this `NumberExpression` and a constant value.
    Specified by:
      `subtract` in interface `NumberExpression`
    Parameters:
      `other` - the constant value
    Returns:
      the new `NumberBinding`

  - ### subtract

    public DoubleBinding subtract(long other)
    Description copied from interface: `NumberExpression`
    Creates a new `NumberBinding` that calculates the difference of this `NumberExpression` and a constant value.
    Specified by:
      `subtract` in interface `NumberExpression`
    Parameters:
      `other` - the constant value
    Returns:
      the new `NumberBinding`

  - ### subtract

    public DoubleBinding subtract(int other)
    Description copied from interface: `NumberExpression`
    Creates a new `NumberBinding` that calculates the difference of this `NumberExpression` and a constant value.
    Specified by:
      `subtract` in interface `NumberExpression`
    Parameters:
      `other` - the constant value
    Returns:
      the new `NumberBinding`

  - ### multiply

    public DoubleBinding multiply(ObservableNumberValue other)
    Description copied from interface: `NumberExpression`
    Creates a new `NumberBinding` that calculates the product of this `NumberExpression` and another `ObservableNumberValue`.
    Specified by:
      `multiply` in interface `NumberExpression`
    Parameters:
      `other` - the second `ObservableNumberValue`
    Returns:
      the new `NumberBinding`

  - ### multiply

    public DoubleBinding multiply(double other)
    Description copied from interface: `NumberExpression`
    Creates a new `NumberBinding` that calculates the product of this `NumberExpression` and a constant value.
    Specified by:
      `multiply` in interface `NumberExpression`
    Parameters:
      `other` - the constant value
    Returns:
      the new `NumberBinding`

  - ### multiply

    public DoubleBinding multiply(float other)
    Description copied from interface: `NumberExpression`
    Creates a new `NumberBinding` that calculates the product of this `NumberExpression` and a constant value.
    Specified by:
      `multiply` in interface `NumberExpression`
    Parameters:
      `other` - the constant value
    Returns:
      the new `NumberBinding`

  - ### multiply

    public DoubleBinding multiply(long other)
    Description copied from interface: `NumberExpression`
    Creates a new `NumberBinding` that calculates the product of this `NumberExpression` and a constant value.
    Specified by:
      `multiply` in interface `NumberExpression`
    Parameters:
      `other` - the constant value
    Returns:
      the new `NumberBinding`

  - ### multiply

    public DoubleBinding multiply(int other)
    Description copied from interface: `NumberExpression`
    Creates a new `NumberBinding` that calculates the product of this `NumberExpression` and a constant value.
    Specified by:
      `multiply` in interface `NumberExpression`
    Parameters:
      `other` - the constant value
    Returns:
      the new `NumberBinding`

  - ### divide

    public DoubleBinding divide(ObservableNumberValue other)
    Description copied from interface: `NumberExpression`
    Creates a new `NumberBinding` that calculates the division of this `NumberExpression` and another `ObservableNumberValue`.
    Specified by:
      `divide` in interface `NumberExpression`
    Parameters:
      `other` - the second `ObservableNumberValue`
    Returns:
      the new `NumberBinding`

  - ### divide

    public DoubleBinding divide(double other)
    Description copied from interface: `NumberExpression`
    Creates a new `NumberBinding` that calculates the division of this `NumberExpression` and a constant value.
    Specified by:
      `divide` in interface `NumberExpression`
    Parameters:
      `other` - the constant value
    Returns:
      the new `NumberBinding`

  - ### divide

    public DoubleBinding divide(float other)
    Description copied from interface: `NumberExpression`
    Creates a new `NumberBinding` that calculates the division of this `NumberExpression` and a constant value.
    Specified by:
      `divide` in interface `NumberExpression`
    Parameters:
      `other` - the constant value
    Returns:
      the new `NumberBinding`

  - ### divide

    public DoubleBinding divide(long other)
    Description copied from interface: `NumberExpression`
    Creates a new `NumberBinding` that calculates the division of this `NumberExpression` and a constant value.
    Specified by:
      `divide` in interface `NumberExpression`
    Parameters:
      `other` - the constant value
    Returns:
      the new `NumberBinding`

  - ### divide

    public DoubleBinding divide(int other)
    Description copied from interface: `NumberExpression`
    Creates a new `NumberBinding` that calculates the division of this `NumberExpression` and a constant value.
    Specified by:
      `divide` in interface `NumberExpression`
    Parameters:
      `other` - the constant value
    Returns:
      the new `NumberBinding`

  - ### asObject

    public ObjectExpression<Double> asObject()
    Creates an `ObjectExpression` that holds the value of this `DoubleExpression`. If the value of this `DoubleExpression` changes, the value of the `ObjectExpression` will be updated automatically.
    Returns:
      the new `ObjectExpression`
    Since:
      JavaFX 8.0