my @captures = 'abcde' =~ m[(.){3}];
print "@captures";;
c

##</code><code>##

my @captures = 'abcde' =~ m[(.)(.)(.)];;
print "@captures";;
a b c

##</code><code>##

'abcde' =~ m[(.){3}] and print "$1,$2,$3";;
Use of uninitialized value in concatenation (.) or string at ...
Use of uninitialized value in concatenation (.) or string at ...
c,,

'abcde' =~ m[(.)(.)(.)] and print "$1,$2,$3";;
a,b,c