my $str = "foo bar baz";
print "[", $str =~ /\w+ /,   "]", $/; # list no capture
print "[", $str =~ /\w+ /g,  "]", $/; # list no capture + /g
print "[", $str =~ /(\w+) /, "]", $/; # list and capture
print "[". $str =~ /\w+ /,   "]", $/; # scalar

__output__

[1]
[foo bar ]
[foo]
[1]