Password REGEX with min 6 chars, at least one letter and one number and may contain special characters

Perhaps a single regex could be used, but that makes it hard to give the user feedback for which rule they aren't following. A more traditional approach like this gives you feedback that you can use in the UI to tell the user what pwd rule is not being met:

function checkPwd(str) {    if (str.length < 6) {        return("too_short");    } else if (str.length > 50) {        return("too_long");    } else if (str.search(/\d/) == -1) {        return("no_num");    } else if (str.search(/[a-zA-Z]/) == -1) {        return("no_letter");    } else if (str.search(/[^a-zA-Z0-9\!\@\#\$\%\^\&\*\(\)\_\+]/) != -1) {        return("bad_char");    }    return("ok");}

following jfriend00 answer i wrote this fiddle to test his solution with some little changes to make it more visual:

http://jsfiddle.net/9RB49/1/

and this is the code:

checkPwd = function() {    var str = document.getElementById('pass').value;    if (str.length < 6) {        alert("too_short");        return("too_short");    } else if (str.length > 50) {        alert("too_long");        return("too_long");    } else if (str.search(/\d/) == -1) {        alert("no_num");        return("no_num");    } else if (str.search(/[a-zA-Z]/) == -1) {        alert("no_letter");        return("no_letter");    } else if (str.search(/[^a-zA-Z0-9\!\@\#\$\%\^\&\*\(\)\_\+\.\,\;\:]/) != -1) {        alert("bad_char");        return("bad_char");    }    alert("oukey!!");    return("ok");}

btw, its working like a charm! ;)

best regards and thanks to jfriend00 of course!

A more elegant and self-contained regex to match these (common) password requirements is:

^(?=.*[A-Za-z])(?=.*\\d)[A-Za-z\\d^a-zA-Z0-9].{5,50}$

The elegant touch here is that you don't have to hard-code symbols such as $ @ # etc.

To accept all the symbols, you are simply saying: "accept also all the not alphanumeric characters and not numbers".

Min and Max number of characters requirement

The final part of the regex {5,50} is the min and max number of characters, if the password is less than 6 or more than 50 characters entered the regex returns a non match.