Attribute: to_string

The pragma affects how the result of converting an enumeration component with the TO_STRING operator is output. If the enumeration declaration has the pragma, then the name of the enumeration component appears as a string instead of the numeric value.

Syntax:

{attribute 'to_string'}

Insert location: First line above the declaration part of the enumeration.

Example 290. example

Declaration of the enumeration color:

{attribute 'to_string'}
TYPE COLOR:
(
    red := 0,
    blue := 1,
    green := 2
);
END_TYPE

Conversion with TO_STRING:

PROGRAM PLC_PRG
VAR
    i_color: COLOR;
    s_show_color: STRING;
END_VAR
i_color := 1;
s_show_color := TO_STRING(i_color);

In this case, s_show_color gets the value 'blue' instead of 1 as the conversion result.