JQuery + Regex: Grouping and Counting - regex

Question

I have been reading and playing with regex used in JQuery, and have got things partially working but don't seem to be tracking on the failing regex.
The specific problem – I think – has to do with 'look[ing]behind'.
Thanks to CodeJockey for the original direction. Here's my updated code:
<script type="text/javascript">
jQuery(document).ready(function($) {
$.validator.addMethod("lccharReqs", function(value, element) {
var lc = /(?=.*[a-z])/;
return this.optional(element) || lc.test(value);
}, "Your password should contain at least one lowercase letter!");
$.validator.addMethod("uccharReqs", function(value, element) {
var uc = /(?=.*[A-Z])/;
return this.optional(element) || uc.test(value);
}, "Your password should contain at least one uppercase letter!");
$.validator.addMethod("nccharReqs", function(value, element) {
var nc = /(?=.*[0-9])/;
return this.optional(element) || nc.test(value);
}, "Your password should contain at least one number!");
$.validator.addMethod("speccharReqs", function(value, element) {
var sc = /(?<=.*[\!\#\#\$\%\&\?\-\_])/;
return this.optional(element) || sc.test(value);
}, "Your password should contain at least one special character!");
$("#new_noisuf_pwd").validate({
rules: {
inf_field_Password: {
required: true,
minlength: 8,
lccharReqs: true,
uccharReqs: true,
nccharReqs: true,
speccharReqs: true
},
pwd_confirm : {
equalTo: "#inf_field_Password"
}
},
messages: {
inf_field_Password: {
required: "Please enter a password!",
minlength: "Your password must be at least 8 characters!",
maxlength: "Your password cannot be more the 12 characters!"
},
pwd_confirm : {
equalTo: "Your passwords does not match!"
}
}});
});
</script>
The reason I'm leaning towards the 'lookbehind' is:
Enter aaaaaaaa - I get the uppercase error...
Enter Aaaaaaaa - I get the number error...
Enter 1Aaaaaaa - I get the special character error, but
Enter Passw0rd - I get no error.
Really trying to learn this and have been reading a lot, but I'm stuck.
Thanks!
[original question]
I am using the 'validation' plugin and am adding a method as follows:
jQuery.validator.addMethod("charReqs", function(value, element) {
return this.optional(element) || /^(([a-z]{1})([A-Z]{1})([0-9]{1})([\!\#\#\+\-]{1})) *$/.test(value);
}, "One lowercase letter, one capital letter, one number and one of the characters listed above - please!");
1.) Do I have the syntax correct to check for 1 l-c char, 1 u-c char, 1 num and 1 of a list of special chars somewhere in the string:
/^ ( ([a-z]{1}) ([A-Z]{1}) ([0-9]{1}) ([\!\#\#\+\-]{1}) ) *$/
2.) Am I grouping this correctly?
3.) If not, please explain.
Thanks

Answer 1

POINT BY POINT ANSWER
1) Not really, no
Your expression specifies a string that begins with exactly one lower case character [a-z], followed by exactly one upper case character[A-Z], followed by exactly one digit [0-9], followed by exactly one of the following characters: !, #, #, +, -, followed by zero or more spaces, then the end of the string :-/
2) Nope - not grouped correctly
3) More complex explanation: the character classes ([a-z], [0-9], etc) are correct enough (though the {1} part and escaping \ characters are redundant. However, you need to have them in what's called a "lookahead" that matches matching anything followed by those characters.
Instead of saying "match one of these"
([a-z])
You would say essentially "lookahead and see if you can match any text followed by one of these, then come back"
(?=.*[a-z])
To match two characters somewhere in the string, you would do like this:
(?=(.*[a-z]){2})
As for the whole expression, to match one of each of the characters you were looking for, use this:
^(?=.*[a-z])(?=.*[A-Z])(?=.*[0-9])(?=.*[\!\#\#\+\-])$
To require two or more of each, you would use the {#} notation, like
^(?=(.*[a-z]){2})(?=(.*[A-Z]){2})(?=(.*[0-9]){2})(?=(.*[\!\#\#\+\-]){2})$
You could also enforce a minimum length (like 10 characters) like
^(?=(.*[a-z]){2})(?=(.*[A-Z]){2})(?=(.*[0-9]){2})(?=(.*[\!\#\#\+\-]){2}).{10,}$
HOWEVER
I would recommend separating these out into separate expressions (I'm guessing something like jQuery.validator.addMethod("...", function(...){...}, "Reason...").addMethod(...).addMethod(...).etc() that each tell the user what's missing. So you'd have one looking for lowercase characters, saying "you need a lower case character", then one looking for digits saying "you need a digit", etc...
Also, the special characters there are really restrictive, so I hope you allow some other ones as well (as long as those are provided (?))
and finally... see http://xkcd.com/936/