質問？？？
以下の２つだとどっちが速いですか

hoge = Words()
-----------------------------
public function Words() as string
dim str as string
for i as integer = 1 to 100
str += "ABCD"
next
return str
end sub
===========================================
dim str as string
hoge = Words(str)
-----------------------------
public sub Words(byref str as string)
for i as integer = 1 to 100
str += "ABCD"
next
end sub