BBC BASIC Programmers' Reference

by Richard Russell, March 2014

LB Booster provides the capability of passing an entire array as a parameter to a SUB or a FUNCTION. Here is a simple example:

      one(5) = 123
      call test one()
      end
 
  sub test two()
      print two(5)
  end sub

To demonstrate that the array two() is genuinely 'local' to the SUB:

      one(5) = 123
      two(5) = 456
      call test one()
      print two(5)
      end
 
  sub test two()
      print two(5)
  end sub

Arrays are automatically passed 'by reference' (you don't need to specify BYREF):

      one(5) = 123
      two(5) = 456
      call test one()
      print two(5)
      print one(5)
      end
 
  sub test two()
      print two(5)
      two(5) = 789
  end sub

But you must use BYREF if you want to REDIM the array inside the SUB (requires LBB v2.53 or later):

      one(5) = 123
      two(5) = 456
      call test one()
      print two(5)
      print one(15)
      end
 
  sub test byref two()
      print two(5)
      redim two(15)
      two(15) = 789
  end sub

Of course you can use a FUNCTION instead of a SUB:

      one(5) = 123
      two(5) = 456
      print test(one())
      print two(5)
      print one(5)
      end
 
  function test(two())
      test = two(5)
      two(5) = 789
  end function