Example 6: Code block variables

This example shows how to use variables defined with the VAR instruction, to be used in a specific scope in the program code.

IMPORT util

TYPE t_rec RECORD
        id INTEGER,
        name VARCHAR(20),
        tags DYNAMIC ARRAY OF STRING
     END RECORD

MAIN
    IF arg_val(1)=="rec1" THEN
       VAR rec1 t_rec = (
           id: -1,
           name: NULL
       )
       DISPLAY util.JSON.stringify(rec1)
    ELSE
       VAR rec2 t_rec = (
           id: -1,
           name: "<undefined>",
           tags: getDefaultTags()
       )
       DISPLAY util.JSON.stringify(rec2)
    END IF
END MAIN

FUNCTION getDefaultName() RETURNS STRING
    RETURN "<undefined>"
END FUNCTION

FUNCTION getDefaultTags() RETURNS DYNAMIC ARRAY OF STRING
    DEFINE arr DYNAMIC ARRAY OF STRING
    LET arr[1] = "foo"
    LET arr[2] = "bar"
    RETURN arr
END FUNCTION

Ouput:


$ fglcomp -M v.4gl && fglrun v.42m rec1
{"id":-1,"tags":[]}

$ fglcomp -M v.4gl && fglrun v.42m rec2
{"id":-1,"name":"<undefined>","tags":["foo","bar"]}