Enumeration

An enumeration consists of a set of named constants, typically representing options or states. Enumerations are strongly typed meaning enumeration variables can only be assigned a value defined in the enumeration type.

• Named values within an enumeration definition must be unique, but multiple enumerations can have a member with the same name
• The first value defined in an enumeration is the default value unless an explicit default value is assigned.
• Only equality and inequality operators can be used.

Syntax

TYPE <EnumName> :
(
    // Members
) := <optional default>;
END_TYPE

Samples

An enumeration for a color

TYPE E_Color :
(
    Red,
    Orange,
    Yellow,
);
END_TYPE

VAR
    color : E_Color;
    name : STRING;
END_VAR

color := color.Yellow;

// Enumerations are commonly used with CASE statements
CASE color OF
    color.Red :
        name := 'Red';
    color.Orange :
        name := 'Orange';
    color.Yellow :
        name := 'Yellow';
END_CASE;

print(name);

A different default value

TYPE E_Color :
(
    Red,
    Orange := 4,
    Yellow,
) := Orange;
END_TYPE

VAR
    color : E_Color;
END_VAR

print(color);  // 4