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