Comparison With Perl

Perl's and Rulz' regexp match operator is //, both default to match $_, both set the $1, $2, etc. and $& special variables.

Basic syntax:

"Hello World" =~ /World/;   # matches (Perl)

/World/ "Hello World"       # matches (Rulz)

Special variables and return:

$_= foobar;
$n = /(foo)/;
print "$_ $n $& $1"         # foobar 1 foo foo

_ foobar
/(foo)/
^ $_ $# $& $1               # foobar 1 foo foo

Rulz' special variable $0 — common "return value" — emulates PHP's preg_match() function's $matches; in this case:

^                           # (foo,foo)

More examples from Perlretut.

Basic conditional:

if ("Hello World" =~ /World/) {
   print "It matches.\n";
}
else {
   print "It doesn't match.\n";
}

Match sense reversed:

if ("Hello World" !~ /World/) {
   print "It doesn't match.\n";
}
else {
   print "It matches.\n";
}

Regexp in variable:

$greeting = "World";
if ("Hello World" =~ /$greeting/) {
   print "It matches.\n";
}
else {
   print "It doesn't match.\n";
}

Basic conditional:

/World/ "Hello World"
? ^"It matches.\n"
! ^"It doesn't match.\n"

Match sense reversed:

/World/ "Hello World"
! ^"It doesn't match.\n"
? ^"It matches.\n"

Regexp in variable:

= g "World"
/$g/ "Hello World"
? ^"It matches.\n"
! ^"It doesn't match.\n"