PROGRAM, CHAIN

A PROGRAM statement declares a program name and parameters, which are used by CHAIN statements.
A CHAIN statement transfers the control to another program and terminates the program itself.


PROGRAM statements

PROGRAM Program_Name
PROGRAM Program_Name(variable, variable，variable，･･･ ，variable)
The naming rule for Program_Name is same as that for numeric variables.
Example.
PROGRAM ABC(a,s$)
When arrays are written as parameters, they are written followed by parentheses and commas of the number of the dimension minus 1.
Example.
PROGRAM SAMPLE(A(),B(,),C(,,))
A is a 1-dimensional array, B 2-dimensional, C 3-dimensional.

A PROGRAM statement must be written in the first line of a program.
When a CHAIN statement has launched this program, the values that the CHAIN statement has handed over are substituted for the parameters.
A PROGRAM statement can be used for a program that is not necessarily written by BASIC to launch the program and hand over some parameters.

Exceptions
extype4301 Parameter mismatch
extype4302 Mismatched dimension of array parameter

CHAIN statements

CHAIN File_Name
CHAIN File_Name WITH ( expression，expression，…，expression )
File_Name is a string expression whose value shall be the name of the file that stores a BASIC program.
The values of expressions written in the WITH-clause shall be the parameters for the PROGRAM statement.
Expressions are numerical expressions, string expressions or arrays.
Arrays are written without parentheses.
Example 1.
CHAIN "FRACTAL\DRAGON.BAS"
Example 2.
CHAIN "A:\ABC.BAS" WITH (12,"Quiz")
Example 3.
DIM A(10),B(3,3),C(2,3,4)
CHAIN "A:\SAMPLE.BAS" WITH(A,B,C)


(Note)
Although the program name that is written in the PROGRAM statement can differ from the name of the file which stores the program, the argument of a CHAIN statement is not a program name but a file name.

Refer to command line parameters