example code #1

MAIN

  DEFINE json_arr util.JSONArray

    LET json_arr = util.JSONArray.create()

    CALL json_arr.put(1, 123)

    CALL json_arr.put(2, "abc")

    CALL json_arr.put(3, null)

    DISPLAY json_arr.toString()  

  CALL fgl_getkey()

END MAIN

example code #2

MAIN

  DEFINE json_arr util.JSONArray

  DEFINE da DYNAMIC ARRAY OF INTEGER

    LET json_arr = util.JSONArray.create()

    LET da[1] = 1

    LET da[2] = 12

    LET da[3] = 123

    CALL json_arr.put(1, da)

    DISPLAY json_arr.toString()  

  CALL fgl_getkey()

END MAIN

obtained results