Dimensions of a array

[fox]

Hi all.
Please, I would like to know what is the simple way to know the dimensions of a array (single dimensioned)  of which I don't Know the number of items.
Thanks to all and bye
fox

[tsh73]

There are NO simple way.

But you don't likely *get* array about which you don't know:
arrays are global in LB, and could not be passed to sub/function.

So array a() in your sub will always be a() elsewhere.
So you might as well store it's dimension in a variable.

---

just for kicks, one could try to access array items until it breaks. Last working would be array size.

n = int(rnd(0)*100)
print n
dim a(n)

print "size of A is ";sizeA()
end

function sizeA()
on error goto [err]
for i = 1 to 100
   dummy=a(i)
next
[err]   'then it die
sizeA = i-1
end function

It could be made fast by using powers of two and binary search.

[tsh73]

Oh, I forgot EVAL
so with EVAL you can pass array into subs. Kind of (only for reading)

n = int(rnd(0)*100)
print n
dim a(n)

print "size of a() is ";sizeA("a")
dim b(7)
print "size of b() is ";sizeA("b")
dim c$(13)
print "size of c$() is ";sizeA("c$")

end

function sizeA(arrName$)
on error goto [err]
for i = 1 to 100
   dummy=eval(arrName$;"(";i;")")
next
[err]   'then it die
sizeA = i-1
end function


[fox]

Thanks a lot, tsh73. Your help will be precious for me.
Anyway I understood that the "simple way" is (as you suggested) to store the dimensions of the array in a variable.
Thanks a lot again and bye
fox