Core Function IsDeclared

IsDeclared( <variable name>, <flag> )

Description

Check if a variable has been declared

Parameters

variable name

String representing name of the variable to be checked.

flag

Optional; Flag to decide the scope to be checked.

0 = ANY scope (Should be Local first then Global) (Default)
1 = Local scope only
2 = Global scope only
3 = Max depth local scope only (Such as a classes My)

Return Value

Success: Returns true if variable has been assigned.

Failure: Returns false if variable doesn't exist yet.

Remarks

It is worth noting that even if the variable is $a = null; it will be considered DEFINED since it does exist

Example

If (!IsDeclared("a"))
    MsgBox('$a is NOT declared');     // $a has never been assigned
 
$a=1;
 
If (IsDeclared ("a"))
    MsgBox('$a IS declared');      //due to previous $a=1 assignment