We've received an assignment from school, where we're supposed to make our own small n' simple Perl application. I thought I'd make a ATM simulator. So far, it's been going great; I've created a menu (Withdraw, Balance, Transfer), by using subroutines. This is my code so far:
#! /usr/bin/perl
#Written by: Tobias Svenblad, h15tobsv@du.se, Digitalbrott & e-Säkerhetsprogrammet (2015)
#PerlLab03-2c.plx
use warnings;
use strict;
use Term::ANSIColor;
use Text::Format;
my $firstname;
my $lastname;
my $acc_balance = 2451.26;
my $acc_withdraw;
my $clr_scr = join( "", ( "\033[2J", "\033[0;0H" ) ); #This variable will clear the screen and jump to postion 0, 0.
my $atm = Text::Format->new;
print color('green');
print $atm->center("ATM v. 1.20");
print color('reset');
#Create account message.
my $crt_acc_msg = <<"END_MSG";
\nDear Sir or Madam,\n
We're very happy you've chose us as your bank.
Before we proceed, we need to set-up your account.\n
END_MSG
print $crt_acc_msg;
&acc_create;
&acc_choose;
sub acc_create {
ACC_BEGINNING:
#First name:
print "\nYour first name: ";
$firstname = <STDIN>;
chomp $firstname;
#Last name:
print "\nYour last name: ";
$lastname = <STDIN>;
chomp $lastname;
if ( defined($firstname) && $firstname ne "" ) {
if ( defined($lastname) && $lastname ne "" ) {
goto ACC_PASS;
}
}
else {
print "You didn't fill in first or last name. Try again. \n";
goto ACC_BEGINNING;
}
ACC_PASS:
print "Please wait while the system loads.\n\n";
#sleep(2);
print $clr_scr;
print color('green');
print $atm->center("ATM v. 1.20");
print color('reset');
print "\nWelcome ", $firstname, " ", $lastname, "!\n\n";
}
sub acc_choose {
sub acc_balance {
print $clr_scr;
print color('green');
print $atm->center("ATM v. 1.20");
print color('reset');
print "\nYour balance is: ";
print color('green');
print $acc_balance;
print color('reset');
print " SEK\n\n";
&acc_choose;
}
sub acc_withdraw {
ENTER_AMOUNT:
print $clr_scr;
print color('green');
print $atm->center("ATM v. 1.20");
print color('reset');
print "\nEnter how much you'd like to withdraw: \n";
my $acc_balance_withdraw = <STDIN>;
if ( $acc_balance_withdraw > $acc_balance ) {
print "Insufficient funds.";
goto ENTER_AMOUNT;
}
$acc_balance -= $acc_balance_withdraw;
print "\nYour current balance is now: ";
print color('green');
print $acc_balance;
print color('reset');
print " SEK\n\n";
&acc_choose;
}
sub acc_transfer {
ENTER_AMOUNT:
print $clr_scr;
print color('green');
print $atm->center("ATM v. 1.20");
print color('reset');
print "\nEnter how much you'd like to transfer: \n";
my $acc_balance_withdraw = <STDIN>;
if ( $acc_balance_withdraw > $acc_balance ) {
print "Insufficient funds.";
goto ENTER_AMOUNT;
}
print "\nYour current balance is now: ";
print color('green');
print $acc_balance - $acc_balance_withdraw;
print color('reset');
print " SEK\n\n";
&acc_choose;
}
ACC_CHOOSE:
print "[ ";
print color('cyan');
print "1";
print color('reset');
print " ]";
print "Account Balance\n";
print "[ ";
print color('cyan');
print "2";
print color('reset');
print " ]";
print "Withdraw\n";
print "[ ";
print color('cyan');
print "3";
print color('reset');
print " ]";
print "Transfer\n";
my $choice1 = <STDIN>;
chomp $choice1;
if ( $choice1 == 1 ) {
&acc_balance;
}
elsif ( $choice1 == 2 ) {
&acc_withdraw;
}
elsif ( $choice1 == 3 ) {
&acc_transfer;
}
else {
print "You entered an invalid option. Try again. \n";
goto ACC_CHOOSE;
}
return ();
}
The problem I face is when I try to return the $acc_balance value to the other subroutines. I've tried to implement return($acc_balance ); underneath the nested subroutines, but that'll just prompt me to end the application. So basically, what I'm trying to do is to update $acc_balance every time I make a withdrawal or transfer (they are both currently the same thing in this code), but whenever I try to do that, it either doesn't update the value or it'll just show the classic "Press any key to continue..." message.
Any help is greatly appreciated! Thanks!
I think you shouldn't be using subroutines for this assignment. But it worries me that someone has told you to use an ampersand & when you call a subroutine and has explained how to use labels and goto. That's inappropriate for a modern computer language and you can do much better
For instance, here's how I would write your subroutine acc_create
sub acc_create {
while () {
print "\nYour first name: ";
chomp (my $firstname = <STDIN>);
print "\nYour last name: ";
chomp (my $lastname = <STDIN>);
last if $firstname and $lastname;
print "You didn't fill in first or last name. Try again.\n";
}
print "Please wait while the system loads.\n\n";
print
$clr_scr,
color('green'), $atm->center("ATM v. 1.20"), color('reset');
print "\nWelcome $firstname $lastname!\n\n";
}
There's a lot more I could say, but Stack Overflow isn't the place for a tutorial