Undefined values: Difference between revisions
Content added Content deleted
m (+output, comment) |
|||
| Line 19: | Line 19: | ||
== Icon and Unicon == |
== Icon and Unicon == |
||
Icon/Unicon don't really have a notion of an undefined variable. There is a [[Undefined_values/Check_if_a_variable_is_defined|null value/data type that can be tested]]. However, it is possible in Unicon to interrogate the environment and obtain the string names of variables in the current (or calling procedures). |
Icon/Unicon don't really have a notion of an undefined variable. There is a [[Undefined_values/Check_if_a_variable_is_defined|null value/data type that can be tested]]. However, it is possible in Unicon to interrogate the environment and obtain the string names of variables in the current (or calling procedures) and determine if a variable is defined. |
||
==={{header|Icon}}=== |
==={{header|Icon}}=== |
||
The functions localnames, paramnames, staticnames, and globalnames don't exist in Icon. |
The functions localnames, paramnames, staticnames, and globalnames don't exist in Icon. |
||