Apple II User Manual

                FNJ7, FNKO, FNR2.  User defined func-

                tions are restricted to one line.  A function

                may be defined to be any expression, but

                may only have one argument.  In the

                example, B and C are variables that are used

                in the program.  Executing the DEF state-

                ment defines the function.  User defined

                functions can be redefined by executing

                another DEF statement for the same

                function.  "V" is called the dummy variable.

                Execution of this statement following the               100 Z=FNA(3)

                above would cause Z to be set to 3/B+C,

                but the value of V would be unchanged.

STATEMENT       SYNTAX/FUNCTION                                         EXAMPLE

DIM             DIM variable (size 1, [size 2...])                      113 DIM A(3),B(10)

                Allocates space for matrices.  All matrix

                elements are set to zero by the DIM

                statement.

                Matrices can have from one to 255                       114 DIM R3(5,5),

                dimensions.                                             D$(2,2,2)

                Matrices can be dimensioned dynamically                 115 DIM Q1(N),Z(2*I)

                during program execution.  If a matrix is

                not explicitly dimensioned with a DIM

                statement, it is assumed to be a single

                dimensioned matrix of whose single

                subscript may range 0 to 10 (eleven

                elements).

                If this statement was encountered before a              117 A(8)=4

                DIM statement for A was found in the

                program, it would be as if a DIM A(10)

                had been executed previous to the execu-

                tion of line 117.  All subscripts start at

                zero (0), which means that DIM X(100)

                really allocates 101 matrix elements.

STATEMENT       SYNTAX/FUNCTION                                         EXAMPLE

END             END                                                     999 END

                Terminates program execution without

                printing a BREAK message.  (See STOP.)

                CONT after an END statement causes

                execution to resume at the statement after

                the END Statement.  END can be used

                anywhere in the program, and is optional.

STATEMENT       SYNTAX/FUNCTION                                         EXAMPLE

FOR             FOR variable = expression to expression                 300 FOR V=1 TO 9.3

                [STEP expression]  (See NEXT statement)                 STEP .6

                V is set equal to the value of the expression

                following the equal sign, in this case 1.  This

                value is called the initial value.  Then the

                statements between FOR and NEXT are

                executed.  The final value is the value of the

                expression following the TO.  The step is

                the value of the expression following STEP.

                When the NEXT statement is encountered,

                the step is added to the variable.

                If no STEP was specified, it is assumed to              310 FOR V=1 TO 9.3

                be one.  If the step is positive and the new

                value of the variable is <= the final value

                (9.3 in this example), or the step value is

                negative and the new value of the variable