I am trying to create regex for below condition:
Allowed characters: letters (a-z) (not case sensitive), min-length: 1, max-length: 255.
Numbers and Special Characters (except @,$,%,^) are only allowed in combination with words (a-z texts).
Consecutive special characters are not allowed.
Numbers (up to 4 together) and/or 1 special character can appear in combination with words.
Ex:
9900Acres
Grey Hound!
[Roy]Media
Cool,boy
are all allowed.
I can't seem to get the hang of it.
I tried creating this regex -
^(?:((([0-9]{0,4})[ ]{0,})([!#&*()<,>.?/{}\[\]_-]{0,1})([0-9]{0,4})[a-zA-Z]{1,255}(([0-9]{0,4})([ ]{0,})([0-9]{0,4}))([!#&*()<,>.?/{}\[\]_-]{0,1}))+){3,}$
but with no success
challenge accepted:
instead of one mega-regex, break it down:
function isValid(text = '') {
if (!text.length || text.length > 255) {
return false;
}
// check if there are more than 4 consecutive numbers
if (/[0-9]{5,}/.test(text)) {
return false;
}
// check if there are 2 consecutive special characters
if (/[!#&*()<,>.?/{}[\]_-]{2,}/.test(text)) {
return false;
}
return true; // should be fine ?
}
console.log(isValid('9900Acres')); // true
console.log(isValid('Grey Hound!')); // true
console.log(isValid('[Roy]Media')); // true
console.log(isValid('Cool,boy')); // true
Try with this:
^(?=.*[A-Za-z])(?!.*[^a-zA-Z\d\n]{2})(?!(?:.*[^\da-zA-Z\n])?\d+(?:[^\da-zA-Z\n].*)?$)[ !#&*()<,>.?\/{}\[\]\w-]{1,255}$
Explained:
^ # Start of line / String
# Lookahead: whatever + some letter
(?=.*[A-Za-z])
# negative lookahead: whatever + 2 consecutive forbidden characters
(?!.*[^a-zA-Z\d\n]{2})
# negative lookahead to forbid numbers without letters on some of the sides:
(?!
(?:.*[^\da-zA-Z\n])? # Optional: something + special character
\d+ # numbers
(?:[^\da-zA-Z\n].*)?$ # Optional: special character + something + end of string
)
# All allowed characters 1 to 255 times
[ !#&*()<,>.?\/{}\[\]\w-]{1,255}
$ # End of line / string
You have a demo here