Variable as a reference or value to a function

[SMcNeill]

Functions will pass by reference in the exact same manner as subs.  The main rule of thumb is that variable types *must* match to pass.

Examples:

Code: (Select All)

DIM x AS INTEGER
x = 0
PRINT Foo(x)
PRINT Foo(x)
PRINT Foo(x)

FUNCTION Foo (X AS INTEGER)
  X = X + 1
  Foo = 2 * X
END FUNCTION

Now, the above will print 2, 4, 6 onto the screen, as the value of X changes and is passed back to the main routine with each run of the function.

Code: (Select All)

DIM x AS _FLOAT
x = 0
PRINT Foo(x)
PRINT Foo(x)
PRINT Foo(x)

FUNCTION Foo (X AS INTEGER)
  X = X + 1
  Foo = 2 * X
END FUNCTION

And the above will print 2, 2, 2 on the screen, as the function Foo uses an Integer, and the main module is passing a _FLOAT.  The two variable types aren't the same, so the value won't pass by reference.

For SUBs and for FUNCTIONs, variables pass by reference as long as the types match.