zero-or-one
Returns a sequence if it contains zero or one items, otherwise errors
Description
The fn:zero-or-one function returns $arg if it contains zero or one items. Otherwise, the error FORG0003 is raised. This function is useful when static typing is in effect, to avoid apparent static type errors.
Parameters |
Description |
|---|---|
arg:item() |
Examples
XPath |
Results |
|---|---|
zero-or-one( () ) |
() |
zero-or-one(‘a’) |
a |
zero-or-one( (‘a’, ‘b’) ) |
Error FORG0003 |