programming-for-dummies

Passing Parameters 221
Figure 6-5:
When you
call a
subprogram,
you may
also need
to pass
parameters
to that
subprogram.
Main program
PrintMyName (5, ”John Smith”)
When you call a subprogram,
you can pass it parameters . . .
5
. . . which get stored in the parameter list
defined by the subprogram.
”John Smith”
SUB PrintMyName (PrintTimes as Integer, Name as String)
FOR I = 1 TO PrintTimes
PRINT Name
NEXT I
END SUB
Subprogram
Book II
Chapter 6
When you call a subprogram, you must give it the exact number and type of
parameters it expects to receive. So the PrintMyName subprogram accepts
two parameters whereas the first parameter must be an integer and the
second parameter must be a string, such as
PrintMyName (4, “Hal Berton”)
PrintMyName (53, “Billie Buttons”)
Breaking a Large
Program into
Subprograms
If you don’t give a subprogram the right number of parameters, your program
doesn’t work. So if a subprogram is expecting two parameters, the following
doesn’t work because they don’t give the subprogram exactly two
parameters:
PrintMyName (4)
PrintMyName (4, 90, “Roberta Clarence”)
The first command doesn’t work because the PrintMyName subprogram
expects two parameters, but this command passes only one parameter.
The second command doesn’t work because this command passes
three parameters, but the PrintMyName subprogram expects only two
parameters.
Another problem is that you give the subprogram the exact number of
parameters, but not the right type of parameters. So this subprogram
expects to receive an integer and a string, so the following subprogram calls
don’t work because they give it the wrong data:
PrintMyName (98, 23)
PrintMyName (“Victor Harris”, 7)
The first command doesn’t work because the PrintMyName subprogram
expects an integer and a string, but this command tries to give it two numbers.