ENUM


Declares an enumerated type.

Syntax:
Enum [typename [ Explicit ] ]
symbolname [= expression] [, ...]
...
End Enum

Parameters:
typename
Name of the Enum
symbolname
Name of the constant
expression
A constant expression
Explicit
Requires that symbols must be explicitly referred to by typename.symbolname

Description:
Enum, short for enumeration, declares a list of symbol names that correspond to discrete values. If no initial value is given, the first item will be set to 0. Each subsequent symbol has a value one more than the previous unless expression is given.

Symbols may be each on their own line, or separated on a single line by commas.

An Enum is a useful way of grouping together a set of related constants. A symbol can be accessed like a constant, e.g: a = symbolname. But if the name clashes with another symbol, it must be resolved using typename.symbolname. This resolution method is always required if you make the enum Explicit.

A non-Explicit Enum declared inside an Extern ... End Extern block will add its constants to the parent namespace directly, as in C, instead of acting as a namespace on its own. It disallows the typename.symbolname style of access, and the constants may conflict with other symbols from the parent namespace.

Enum can not contain any member procedure or member data (only symbols), but it can be included (named or unnamed) in a Type by having.

An Enum instance can be passed, as any user defined instance, to a procedure (including for the definition of Overloaded operators).
The size of an Enum instance will be always that of an Integer (no matter how many defined symbols are just declarations for the compiler assignment).

Examples:
Enum MyEnum
    option1 = 1
    option2
    option3
End Enum

Dim MyVar As MyEnum

MyVar = option1

Select Case MyVar
    Case option1
        Print "Option 1"
    Case option2
        Print "Option 2"
    Case option3
        Print "Option 3"
End Select


Dialect Differences:

Differences from QB:
See also:
Back to User Defined Types
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