Re^2: Changing the Value Assigned To A Hash Key

I had wondered if == "1" was the best technique. This is alllmost my first ever Perl script.

A number of quick functions are used to check user data against input criteria (for checking telephone numbers, postal codes, etc.). The code below is for checking a persons first or last name; one of many checks on this form. All we want to do is verify that more than two characters of an acceptable type are used.

sub check_name {
    my $name = $_[0];
    if ($name =~ /^[A-Z][A-Za-z\-']{2,40}/s) {
        return 1;
    } else {
        return "Friendly message...";
    }
}
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I wanted to return true or false, but wasn't sure how to incorporate an error message anywhere in the many scripts that call this function. It seemed OK to return a true of OK and a string warning if bad. Running with that idea, the "($first_name_check == "1")" test seemed to be the way to go.

It crossed my mind to move the all error messages to a seperate file and return error codes greater than one as index references in the seperate error message file. I haven't seen any good examples of accomplishing this task and would certainly appreciate suggestions on where to go look/read. (All I have is an old Perl cookbook that just seems wrong...

Switch undef around. Thanks for both your suggestions

# was $app{"first_name"} = ""; switch to next line
undef $app{"first_name"};
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Re^3: Changing the Value Assigned To A Hash Key by cog (Parson) on Feb 08, 2005 at 21:23 UTC
Your code doesn't check if two characters are used; it checks if one of `[A-Z]` is used plus two to fourty of `[A-Za-z\-']`. If you really want at least two characters and the first one must be in `[A-Z]`, use this instead: `[A-Z][A-Za-z\-']+`. It does the trick :-) As for returning the warning string, I don't think that's a good idea, because both 1 and "Friendly message..." evaluate to a true value; hence, the caller won't be able to tell the difference easily. Return 0 or undef in case there's something wrong. This way, you can do something like `if ($first_name_check) {`. The Cookbook sure is a good book, but I'd advise you to buy the Learning Perl. Trust me, it'll be worth the money and you'll enjoy the reading :-)	[reply] [d/l] [select]

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Re^3: Changing the Value Assigned To A Hash Key
by cog (Parson) on Feb 08, 2005 at 21:23 UTC

[A-Z]

[A-Za-z\-']

If you really want at least two characters and the first one must be in [A-Z], use this instead: [A-Z][A-Za-z\-']+. It does the trick :-)

As for returning the warning string, I don't think that's a good idea, because both 1 and "Friendly message..." evaluate to a true value; hence, the caller won't be able to tell the difference easily. Return 0 or undef in case there's something wrong. This way, you can do something like if ($first_name_check) {.

The Cookbook sure is a good book, but I'd advise you to buy the Learning Perl. Trust me, it'll be worth the money and you'll enjoy the reading :-)

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