passing a single array value byref?

[MrHiggins]

Hi,

It seems passing an array value by ref does not change the array elements value after the subroutine has completed? Whilst I understand you can't pass a whole array to a subroutine, I would have expected to be able to pass an array element by ref like it was a normal variable.

Here is some example code demonstrating

print "This creates a value and then passes value by ref"
val = 42
print "val is "; val
call changeNumber val
print "val is change to "; val
print
print "Now we will pass a single array value by ref"
print
dim numbers(0)
numbers(0) = 42
print "numbers(0) is "; numbers(0)
call changeNumber numbers(0)
print "numbers(0) is is still? "; numbers(0)

sub changeNumber byref number
   print "The value passed to changeNumber is "; number
   number = 10
   print "value in changeNumber has been changed to "; number
end sub



[Rod]

Yes, unfortunately not. We cannot pass whole arrays and while an element seems to pass byref certainly does not work. Its all to do with arrays being global by default. I think you would have similar problems passing a global variable. Since both arrays and global variables are visible within subs and functions Liberty expects they be changed directly in the sub or function. Bug? not qualified to say.

[mknarr]

Try This.

dim numbers( 0)
numbers(0) = 42
print "numbers(1) is "; numbers(0)
call changeNumber numbers(0)
print "numbers(1) is is still? "; numbers(0)
end

sub changeNumber byref number
print "The value passed to changeNumber is "; number
number = 10
numbers(0)=number 'I put the new number in the array.  You can use a variable instead of 0
print numbers(0)
print "value in changeNumber has been changed to "; number
end sub

[Walt Decker]

Mr. Higgins, an alternate method:

'
DIM Chars$(20)

Chars$(0) = "ABC"

Chars$(0) = FN.SetChar$(Chars$(0))
PRINT Chars$(0)

END

FUNCTION FN.SetChar$(A$)

PRINT A$
A$ = "DEF"

FN.SetChar$ = A$
END FUNCTION
'

[MrHiggins]

Thanks for the ideas guys. The solution I've gone for in my working version is based on mknarr where instead of passing the value by ref I pass the indices of the array items.