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Answer: how do i work this

by Russ (Deacon)
on May 12, 2000 at 06:17 UTC ( #11230=categorized answer: print w/replies, xml ) Need Help??

Q&A > input and output > How can I validate user input? - Answer contributed by Russ

Here's one way to do this:
my $start = $ARGV[0]; while (1){ print "Please Enter the Start-Level (0-7,?)[0]: "; chomp($start = <>); # Check for non-numeric characters if ($start =~ /\D/){ print "\nPlease enter a number (0-7) or ? for help\n"; next; } last if 0 <= $start and $start <= 7; # Check for a help request if ($start eq '?') { print " **** internally coded help information **** \n"; next; } print "\nPlease enter a number between Zero and Seven, inclusive\n"; } print $start;
First, we check that the input is numeric (as you started to do in your commented-out code) to prevent errors if the user enters non-numeric characters.
If the input is valid, we just exit the loop.
If not, check for a help request and, if not '?', print a generic error message and redo the loop.

There are a million different ways to do this, and this is only one of them...


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