Description
The functx:is-a-number function returns true if the value is number (can be cast to a numeric type) and is not the value NaN. If the argument is the empty sequence or a zero-length string, it returns false.
Arguments and Return Type| Name | Type | Description |
|---|
$value |
xs:anyAtomicType? |
the value to test |
| return value |
xs:boolean |
XQuery Function Declaration| See XSLT definition. | | XQuery Syntax for January 2007 (1.0): |
|---|
declare namespace functx = "http://www.functx.com";
declare function functx:is-a-number
( $value as xs:anyAtomicType? ) as xs:boolean {
string(number($value)) != 'NaN'
} ; | | XQuery Syntax for July 2004 - November 2005 (CR): |
|---|
declare namespace functx = "http://www.functx.com";
declare function functx:is-a-number
( $value as xdt:anyAtomicType? ) as xs:boolean {
string(number($value)) != 'NaN'
} ; | | XQuery Syntax for May 2003: |
|---|
declare namespace functx = "http://www.functx.com"
define function is-a-number
( $value as xdt:anyAtomicType? ) as xs:boolean {
fn:string(fn:number($value)) != 'NaN'
} |
Exampleslet $in-xml := | <in-xml>
<a>123</a>
<b>abc</b>
</in-xml> | return |
| XQuery Example | Results |
|---|
functx:is-a-number('123')
|
true
|
functx:is-a-number(123)
|
true
|
functx:is-a-number(' 123 ')
|
true
|
functx:is-a-number('')
|
false
|
functx:is-a-number('123abc')
|
false
|
functx:is-a-number('NaN')
|
false
|
functx:is-a-number($in-xml/a)
|
true
|
functx:is-a-number($in-xml/b)
|
false
|
See Also| fn:number | Converts a value or a node to a number |
History |
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