Duration.Subtract(Duration) Method

  • Reference

Definition

Namespace:
Javax.Xml.Datatype
Assembly:
Mono.Android.dll

Computes a new duration whose value is this-rhs.

[Android.Runtime.Register("subtract", "(Ljavax/xml/datatype/Duration;)Ljavax/xml/datatype/Duration;", "GetSubtract_Ljavax_xml_datatype_Duration_Handler")]
public virtual Javax.Xml.Datatype.Duration? Subtract (Javax.Xml.Datatype.Duration? rhs);
[<Android.Runtime.Register("subtract", "(Ljavax/xml/datatype/Duration;)Ljavax/xml/datatype/Duration;", "GetSubtract_Ljavax_xml_datatype_Duration_Handler")>]
abstract member Subtract : Javax.Xml.Datatype.Duration -> Javax.Xml.Datatype.Duration
override this.Subtract : Javax.Xml.Datatype.Duration -> Javax.Xml.Datatype.Duration

Parameters

rhs
Duration

Duration to subtract from this Duration.

Returns

Duration

New Duration created from subtracting rhs from this Duration.

Attributes
RegisterAttribute

Exceptions

IllegalStateException

If two durations cannot be meaningfully subtracted. For example, subtracting one day from one month causes this exception.

NullPointerException

If the rhs parameter is null.

Remarks

Computes a new duration whose value is this-rhs.

For example:

"1 day" - "-3 days" = "4 days"
            "1 year" - "1 day" = IllegalStateException
            "-(1 hour,50 minutes)" - "-20 minutes" = "-(1hours,30 minutes)"
            "15 hours" - "-3 days" = "3 days and 15 hours"
            "1 year" - "-1 day" = "1 year and 1 day"

Since there's no way to meaningfully subtract 1 day from 1 month, there are cases where the operation fails in IllegalStateException.

Formally the computation is defined as follows. First, we can assume that two Durations are both positive without losing generality. (i.e., (-X)-Y=-(X+Y), X-(-Y)=X+Y, (-X)-(-Y)=-(X-Y))

Then two durations are subtracted field by field. If the sign of any non-zero field F is different from the sign of the most significant field, 1 (if F is negative) or -1 (otherwise) will be borrowed from the next bigger unit of F.

This process is repeated until all the non-zero fields have the same sign.

If a borrow occurs in the days field (in other words, if the computation needs to borrow 1 or -1 month to compensate days), then the computation fails by throwing an IllegalStateException.

Java documentation for javax.xml.datatype.Duration.subtract(javax.xml.datatype.Duration).

Portions of this page are modifications based on work created and shared by the Android Open Source Project and used according to terms described in the Creative Commons 2.5 Attribution License.

Applies to

See also