unless|until|LABEL|{}|last|next|redo| || |//|i++|++i

#!/usr/bin/perl

use strict;
use warnings;

$_ = 'oireqo````';

unless($_ =~ /^a/m){print "no match to a
"}

#no match to a

if(!($_ =~ /^a/m)){print "no match to a
"}

#no match to a

unless($_ =~ /^o/m){print "no match to a"}else{print "match!
"}

my $number = 1;

while($number<12)
{
    $number++;print "$number
";
}

#2
#3
#4
#5
#6
#7
#8
#9
#10
#11
#12

until($number<2)
{
    $number--;print "$number
"
}

#11
#10
#9
#8
#7
#6
#5
#4
#3
#2
#1

print "match!
"if($_ =~ /^o/m);

#match!

my @arr=(1,2,3,4,5,6,7);print foreach(@arr);print"
";

#1234567

#my @arr_1=(1,2,3,4,5,6,7);print"$k" foreach my $k($#arr_1);print"
";
#Global symbol "$k" requires explicit package name (did you forget to declare "my $k"?) at t.pl line 62.
#syntax error at t.pl line 62, near "$k("
#Execution of t.pl aborted due to compilation errors.

{
    my $k = "good";
}
#print "$k
";

#Global symbol "$k" requires explicit package name (did you forget to declare "my $k"?) at t.pl line 70.
#Execution of t.pl aborted due to compilation errors.

my @fruit = ('apple','banana','peach','apple','apple');my %match;$match{$_}++ foreach(@fruit);print "$match{$_}
"foreach(keys %match);

#1
#1
#3

my $five_1= 5;my $six_1 = $five_1++;print "$six_1	$five_1
";
my $five_2= 5;my $six_2 = ++$five_2;print "$six_2	$five_2
";

#5       6
#6       6

my %seen;foreach(@fruit) {print "i 've get $_!
" if $seen{$_}++;}

#i 've get apple!
#i 've get apple!

for($_ = "abcdefg";s/(.)//;){print "$1
";if($1 eq "f"){last;}}

#a
#b
#c
#d
#e
#f
my %seen;

READ:while(<>)
{
    foreach(split)
    {
        next READ if /W/;$seen{$_}++;
    }
}

foreach (keys %seen){print "last:$_ is $seen{$_}
";last if /dewm/;}
foreach (keys %seen){print "next:$_ is $seen{$_}
";next if /dewm/;}
#foreach (keys %seen){print "redo:$_ is $seen{$_}
";redo if /dewm/;}

# cat 1.txt
# shsjsk   123
# dewm
# shsjsk   123
#  shsjsk   123
#  shsjsk   123
# cat 1.txt |perl t.pl
#last:shsjsk is 4
#next:shsjsk is 4
#next:123 is 4
#next:dewm is 1
#redo:dewm is 1
#……

my $zero = 0;my $one = 1;
if (($zero != 0)&&($one%$zero==2)){print "get!
"}

#

my %zoo;$zoo{'fish'}='cat',$zoo{'mouse'} ='dog';$zoo{'dog'}="";
my $animal=$zoo{'dog'}||'nobody';print "$animal
"; 
my $animal_1=$zoo{'panda'}||'nobody';print "$animal_1
";
my $animal_2=defined $zoo{'dog'}? '1':'nobody';print "$animal_2
"; 
my $animal_3=$zoo{'dog'}//'nobody';print "$animal_3
"; 

#nobody
#nobody
#1
#

printf "%s
",$animal_3//'nobody';

#

my $m =12;($m>20)||print "$m
";

#12

$m>20 or die "wrong judgement";

#wrong judgement at t.pl line 152, <> line 5.