Enum

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Enum

Declares an enumerated type.

Syntax

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

Parameters

• typename
• symbolname
• expression
• 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).

Remarks

Dialect Differences

• Explicit Enum not available in the -lang qb dialect unless referenced with the alias __Explicit.

Differences from QB

• New to FreeBASIC

See also

• Const
• Operator
• Table with variable types overview, limits and suffixes

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

You can reference formerly declared symbol names within the same enum:

Enum MyEnum

    option1 = 1

    option2

    option3

    __

    MAX_VALUE = __ -1

End Enum

Print "Option #1:", MyEnum.option1

Print "Option #2:", MyEnum.option2

Print "Option #3:", MyEnum.option3

Print "Max Value:", MyEnum.MAX_VALUE

Output:

Option #1:     1
Option #2:     2
Option #3:     3
Max Value:     3

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Category: User Defined Types
Kind: keyword

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Reproduced from the FreeBASIC Wiki Manual under the GNU Free Documentation License 1.3 — with no Invariant Sections, no Front-Cover Texts and no Back-Cover Texts. Copyright © the FreeBASIC project and wiki contributors. See License.