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

print"###simple calculator program##\n\n";

my $opt2 = "y";
my %operations = (  "+" => sub { return $_[0] + $_[1]},
					"-" => sub { return $_[0] - $_[1]},
					"*" => sub { return $_[0] * $_[1]},
					"/" => sub { return $_[0] / $_[1]} );
					
while ($opt2 eq "y"){
    print "enter the first number\n";
    chomp( my $num1 = <> );
    
    print "enter the second number\n";
    chomp( my $num2 = <> );
    
    print "enter your option\n\+ for addition\n\- for subtraction\n\* for multiplication\n\/ for divison\n option:";
    
    chomp(my $opt = <>);
    print "you have entered wrong option\n" and next unless defined $operations{$opt};
    print "you pressed the $opt key\n";
    print $operations{$opt}->( $num1, $num2), "\n\n";
    print "do you want to continue press y or n?\n";
    chomp ($opt2 =<>);
}