box-o-sand/PracticingPerl/cli/operators.pl

#!/usr/bin/env perl
use strict;
use warnings;
use 5.0100;


sub println {
    local $, = "";
    print +(@_ ? @_ : $_), $/;
}


println(4 % 3);

println(4 % 2);

println(-4 % 3);

println(4 ** 2);

println(2 ** (1/2));

my $foo = 1;

println($foo--);

println($foo);

println("dog");

$foo = 1;

println(--$foo);

println($foo);

$foo = 'd';

println(--$foo);

println($foo);

$foo = 'Z';

println($foo++);

println($foo);

$foo = 'Hello';
$foo .= ', world';
println($foo);

my $bar = '+';
$bar x= 6;
println($bar);

print '$a = ';
my $a = <STDIN>;
print '$b = ';
my $b = <STDIN>;
print '$c = ';
my $c = <STDIN>;


my $ncookies = 0;

sub printcookies {
    println("I like cookies " . $ncookies++);
}


if ($a == 5 && $b == 2) {
    printcookies();
}


if ($a == 5 && $b == 2 || $c == 2) {
    printcookies();
}


if ($a == 5 and ($b == 2 || $c == 3)) {
    printcookies();
}


if ($a == 5 && $b == 2 or $c == 3) {
    printcookies();
}


if ($a == 5 && $b == 2 or $c == 3) {
    printcookies();
}


if (($a == 5 && $b == 2) or $c == 3) {
    printcookies();
}


($a, $b) = (5, 2);
if ($a == 4 && $b < 3) {
    printcookies();
}

sub foo {
    return ($c eq 0);
}

foo() or print "foo() failed\n";


print 'Hello' . ' world';
print "\n";

my $str = "hi";
my $repeated_str = $str x 5;
println("$repeated_str");

println($repeated_str eq 'hihihihihi');

println($str ne 'hi');

$str =~ s/i/m/g;
println($str);


print 'A' .. 'Z', "\n";
print 'a' .. 'z', "\n";
print 'A' .. 'z', "\n";
print 1 .. 20, "\n";
print '&' .. '!', "\n";
print 10 .. -10, "\n";
print "$_\n" foreach 1 .. 10, "\n";


my $scalar = 'hi';
my @array = qw(one two three);
my %hash = (
    hi => 1,
    ho => 2,
    he => 3,
);

if ($scalar ~~ @array) {
    print "scalar matches array\n";
}
if ($scalar ~~ %hash) {
    print "scalar matches hash\n";
}
if (@array ~~ %hash) {
    print "array matches hash\n";
}