Is there a way in one single Reg Expression to validate a password string that satisfies,

1. Must have at least one upper case letter [A-Z]
2. Must have at least one lower case letter [a-z]
3. Must have at least one number [0-9]
4. Must have at least one special character from [! $ % ^ & * ( ) _ + = < > ? / \ | ] [ { }]
5. The string length should be between 6 and 25.

Note: The above said steps 1-4 characters can appear in any random order.

I have a solution, but the problem with this one is, I have to check for each named group,
"^((?<lower>[a-z])|(?<upper>[A-Z])|(?<number>[0-9])|(?<symbol>[\\$\\!\\%\\^\\#]))+$"

In C# code I would check as,

if (aMatch.Success && aMatch.Groups["lower"].Success
&& aMatch.Groups["upper"].Success && aMatch.Groups["number"].Success
&& aMatch.Groups["symbol"].Success)
{
Valid Password;
}
else
Not valid;

Is there a better solution, such as writing the whole thing in one Reg Expression?

Thanks,
Chandra

Hello Chandra,

The question you have raised was an excellent one. I don't have great experiences with writing regexs, but in the light of the theoretical knowledge on the subject, following is my comment on it:

As I see it, it is possible to write a better regular expression. However, I feel it will be too complicated and probably an overkill for the problem at hand.
Since there is no specific order with which the lower-case/upper-case/numbers/sp-chars may appear, there will be 24 different terms that would have to be OR-ed.

Lemme know if you find a better way to solve this problem.


Sreeram