Functions
While writing programs you may
need to repeat the same sequence of
instructions in several parts of the program. sdlBasic offers you the
chance of write the instruction sequence one time and then recall it
from every part of the program may needs it.
Variables used inside the function are
local variables, that means they
will not influence other variables that happens to use the same
variable name in your main program or in any other function. This is
valid for arrays too.
See Global Shared Dim Commons statements
for more details.
You can pass to the function a list of
parameters containing the
informations to be processed from the function itself. Functions that
do not require input parameters can be called from your main program
without using brackets. Functions can optionally return
values,specified by the Return statement.
sdlBasic borrows the return statement from
C. In addition to the
standard method of returning values from functions:
function add( a, b )
add = a
+ b
end function
you can also write:
function add( a, b )
Return a
+ b
end function
sdlBasic exits the function at the
point the return statement is executed.
You can simply call the function by the following statement:
newSumm= add( 3, 4)
in this example, variable newSumm will
be set to 7 as returned buy function.
You can choose to simply ignore the result of a function, and treat it
like a subroutine:
' Ignore the return value of Len()
len("123")
the returned value will be lost.
Function name can't be the same of variables or arrays used in the
program with the same scope. This mean you can't use the following code:
myVariable = 1
function myVariable()
...
end function
but you are allowed to use this:
function myFuntion()
myVariable=1
end function
function myVariable()
...
end function