A doubt in Regular Expression

Emeraldgirl

I have a question about regular expression. I want to validate a field using regular expression. I want the first character of the field to be a capital letter and the rest of the characters to be small. How can I do that.
This is what I am doing but it is not working:

(^{[A_Z]{1})([a-z]+)}

Is this right

icthus

how about this:
http://www.php.net/manual/en/function.ucfirst.php

Jim

Emeraldgirl

Thank you for the prompt reply Icthus,

But what I am trying to do is, I already have the structure of each field defined in regular expression. (I am using Perl and Javascript for my validation). When a user enters a value in a field the script will check the value against the predefined structures which are in regular expression patterns and if it doesn't match then I pop up a message box alerting the user about the wrong data. So in this case I want one of the fields starting with an uppercase letter and the rest of the characters can be lower case. So I just want to define the regular expression correctly. Apparently the one I have defined is not working correctly.
For eg: I am defining for a field that the pattern should be
[^{([A_Z]{1}[a-z]+)]} and when a user enter 'book' as a value for this field then it should be counted as wrong and if the value is 'Book' then it should be right.

So I don't need any function for this I just want to know the regular expression pattern that would make it possible

wizkid

Hi,

try following:

$s = "Book";

if(ucfirst(strtolower($s)) == $s) {
  echo "True.";
} else {
  echo "False.";
}

wizkid

Hi,

or you could use (should work 😉):

$s = "Book";

if(preg_match("/^([A-Z]{1})+([a-z]*)$/", $s)) {
  echo "True.";
} else {
  echo "False.";
}

wizkid

Emeraldgirl

Yes it is something like this I was looking for. But unfortunately this definition is not working for me. I am usning in Perl and Javascript combined.
For eg: I have a variable "name"(It is not for person's name it is something else,anyway) the pattern defined as :-

semiote_hash["name"] = "[^{[A_Z]{1}+[a-z]*$]::g";}

so when the user enters the value for this field it is checked against this predefined pattern and if it doesn't match then it is displayed to the user asking him/her to change the value. These are defined in a javascript file and when the user submits it loads the cgi files and does the rest of the work.

Hey wizkid, the above one is the one you suggested but that too is not working. But thanks for the reply

pdata

wizkid's code is working well for me

Thanks!

bad_goose

If you're using Perl instead of PHP, the above code would look like this:

$s = 'Book';

if ($s =~ m/^[A-Z][a-z]*$/) {
    print 'True.';
} else {
    print 'False';
}

Perl regular expressions are awesome.

Weedpacket

Originally posted by bad_goose
Perl regular expressions are awesome.

In PHP the regular expression would be the same (/^{[A-Z][a-z]*$/);} that's why they're called Perl-Compatible Regular Expression.

bad_goose

Yep. They're awesome.