Now we move to the next step, which involves partitioning the
categories that we just identified into choices. And these choices are the
interesting cases for each category. So the interesting subdomains for each one
of these categories. So once more, lets look at that using our
example, the split program. So lets start by considering length. What are
the interesting cases when we think about the length of a string?
Some of those we already saw, one interesting case is the case
of the length of size zero, so a string with no characters.
Another interesting case is the one in which the length of the
string is size minus one, so the string is just one character
short of the size at which it will be cut by the
split program. And we can continue along these lines, so we will select
size, size plus one, size twice the value of size minus one,
and so on and so forth. But even without listing all of
those, I'm sure you get the idea of what it means to
identify this interesting cases. Let's see
the movements that are considering the content.
So without the interesting cases when we think about the content
of the string. So possible interesting case is the string that
contains only spaces. Why? Well maybe because a split is written
spaces in a special way. Similarly a string that contains special
characters, like non printable characters,
like tabulation characters, new line might
also be an interesting case, something that we want to test. Also
in this case we could continue and go on and on.
So basically here you just want to put all the interesting cases
that you can think of when you consider the content
of a string. Now let's move to the value as the
next category. So the value of the input size. And
here we might want to consider a size zero, special case, a
normal situation, like size greater than zero, another special case,
size less than zero or maxint. And these are, if you
remember, I accepted the cases that we consider when we look
at this example, before. And also here we can continue and
go on and on. So, at the end of the
step, what we have is a set of interesting cases
for each one of the categories, and now we can
start to think about how we want to combine them.