Re: (jeffa) Re: simple menu loop problems

okay i understand the array part, but what is
- while (1) doing (is that saying "while True"?)
- menu() what is this doing?
- what is this line doing:
print map { ($_+1).": $choice$_\n" } (0..$#choice);
Thanks
Bob


my $input;
my @choice = (
   'Cancel FINAL Schedule for machine A',
   'Submit new FINAL schedule',
   'Ignore Wrkld',
   'Run around the block',
   'Buy a new car',
   'order Pizza',
   'exit',
);

while (1) {
   menu();
   chomp ($input = <>);
   last if $input == 7;
   print "You have chosen option $input\n";
}

sub menu {
   print "Enter a number for the option you want\n";
   print map { ($_+1).": $choice[$_]\n" } (0..$#choice);
}
[download]

Comment on Re: (jeffa) Re: simple menu loop problems Download Code

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(jeffa) 3Re: simple menu loop problems by jeffa (Bishop) on Mar 12, 2002 at 21:29 UTC
Hey ddrumguy! (got your email BTW ;)) Yes. while(1) is saying while TRUE ... the reason i use that is because Perl has the last token to exit. I used to be afraid of while(1) loops, but i like them now. menu() is just calling the menu subroutine. tye gets on to me for calling subs this way ... a more proper way would be to use the ampersand: &menu(). The main reason i can think of is ... what if a new built-in function named menu is introduced? Then menu() would call it, not the one you declared - but &menu() will call yours. Last item ... hehehe sorry about that. How about this instead: `my $total_choices = $#choice; for my $index (0..$total_choices) { print $index + 1, ": $choice[$index]\n"; }` [download] Same thing ;) Keep it up, you'll be coding map's and grep's and Schwartzian Transforms in no time. ;) Still get good ddrum offers? ;) jeffa L-LL-L--L-LL-L--L-LL-L-- -R--R-RR-R--R-RR-R--R-RR B--B--B--B--B--B--B--B-- H---H---H---H---H---H--- (the triplet paradiddle with high-hat)	[reply] [d/l]

Replies are listed 'Best First'.

(jeffa) 3Re: simple menu loop problems
by jeffa (Bishop) on Mar 12, 2002 at 21:29 UTC

ddrumguy

Yes. while(1) is saying while TRUE ... the reason i use that is because Perl has the last token to exit. I used to be afraid of while(1) loops, but i like them now.
menu() is just calling the menu subroutine. tye gets on to me for calling subs this way ... a more proper way would be to use the ampersand: &menu(). The main reason i can think of is ... what if a new built-in function named menu is introduced? Then menu() would call it, not the one you declared - but &menu() will call yours.
Last item ... hehehe sorry about that. How about this instead:

my $total_choices = $#choice;
for my $index (0..$total_choices) {
   print $index + 1, ": $choice[$index]\n";
}
[download]

Keep it up, you'll be coding map's and grep's and Schwartzian Transforms in no time. ;)

Still get good ddrum offers? ;)

jeffa

L-LL-L--L-LL-L--L-LL-L--
-R--R-RR-R--R-RR-R--R-RR
B--B--B--B--B--B--B--B--
H---H---H---H---H---H---
(the triplet paradiddle with high-hat)

[reply]
[d/l]