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Statements Used to Define and Call BASIC Procedures
 
Task              Statement         Action
═════════════     ═══════════════   ═══════════════════════════════════════
Defining a        FUNCTION          Declares the name, the parameters, and
procedure                           the return type of a FUNCTION procedure.
 
                  SUB               Declares the name and the parameters of
                                    a SUB procedure.
 
Calling a         CALL (BASIC)      Transfers control to a BASIC SUB
procedure                           procedure. (The CALL keyword is
                                    optional.)
 
Exiting from      EXIT FUNCTION     Causes an immediate exit from a
a procedure                         FUNCTION procedure.
 
                  EXIT SUB          Causes an immediate exit from a
                                    SUB procedure.
 
Declaring         DECLARE (BASIC)   Declares a BASIC FUNCTION or SUB
procedure                           procedure and, optionally, specifies
references to a                     the number and type of its parameters.
procedure
 
Sharing           COMMON            Shares variables among separate
variables                           modules. When used with the SHARED
among modules,                      attribute, it shares variables among
procedures,                         different procedures in the same
or programs                         module. Also, passes variable values
                                    from current program to new program
                                    when control is transferred with the
                                    CHAIN statement.
 
                  SHARED            Gives a SUB or FUNCTION procedure
                                    access to variables declared at the
                                    module level without passing them as
                                    parameters.
 
 
Preserving        STATIC            Makes simple variables or arrays local
variable                            to a DEF FN function or a SUB or
values                              FUNCTION procedure, and preserves
                                    values between calls.
 
Transferring      CHAIN             Transfers control from current
to another                          program in memory to another program;
program                             use COMMON to pass variables to the new
                                    program.
 
                  RUN               Restarts the program currently in memory,
                                    or executes a specified program.