You should have tried your hunch. That’s how to do it.
my $first = (split /\./, "hello.world")[0];
You could use a list-context assignment that grabs the first field only.
my($first) = split /\./, "hello.world";
To print it, use
print +(split /\./, "hello.world")[0], "\n";
or
print ((split(/\./, "hello.world"))[0], "\n");
The plus sign is there because of a syntactic ambiguity. It signals that everything following are arguments to print. The perlfunc documentation on print explains.
Be careful not to follow the print keyword with a left parenthesis unless you want the corresponding right parenthesis to terminate the arguments to the print; put parentheses around all arguments (or interpose a
+, but that doesn’t look as good).
In the case above, I find the case with + much easier to write and read. YMMV.