Perl Programming/Keywords/ref
The ref keyword
The ref function returns a non-empty string, if EXPRESSION is a reference and an empty string otherwise. Without EXPRESSION, $_ will be used. The returned value depends on the thing referenced to.
ref knows the following types:
| Type | Notes |
|---|---|
| ARRAY | reference to an array |
| CODE | |
| FORMAT | |
| GLOB | |
| HASH | reference to a hash |
| IO | |
| LVALUE | reference to an lvalue that is not a variable |
| REF | reference to a reference |
| Regexp | regular expression resulting from qr// |
| SCALAR | reference to a scalar |
| VSTRING |
If the referenced object has been blessed into a package, the name of that package is returned instead. This, however, is now considered "bad practice".
Syntax
ref EXPRESSION ref