VCL is a statically typed language.
These types all have implicit conversions to strings, such that their values may be used in contexts where a
STRING value is necessary.
IP types may be
not set (as opposed to being set to the empty string), in which case the variable is considered to have no value. Various functions and operators treat
not set differently; some render them as the empty string, and some as
"(null)". This handling is a property of the function (or operator), rather than a property of the type.