Regex for password must contain at least eight characters, at least one number and both lower and uppercase letters and special characters
Solution 1:
Minimum eight characters, at least one letter and one number:
"^(?=.*[A-Za-z])(?=.*\d)[A-Za-z\d]{8,}$"
Minimum eight characters, at least one letter, one number and one special character:
"^(?=.*[A-Za-z])(?=.*\d)(?=.*[@$!%*#?&])[A-Za-z\d@$!%*#?&]{8,}$"
Minimum eight characters, at least one uppercase letter, one lowercase letter and one number:
"^(?=.*[a-z])(?=.*[A-Z])(?=.*\d)[a-zA-Z\d]{8,}$"
Minimum eight characters, at least one uppercase letter, one lowercase letter, one number and one special character:
"^(?=.*[a-z])(?=.*[A-Z])(?=.*\d)(?=.*[@$!%*?&])[A-Za-z\d@$!%*?&]{8,}$"
Minimum eight and maximum 10 characters, at least one uppercase letter, one lowercase letter, one number and one special character:
"^(?=.*[a-z])(?=.*[A-Z])(?=.*\d)(?=.*[@$!%*?&])[A-Za-z\d@$!%*?&]{8,10}$"
Solution 2:
You may use this regex with multiple lookahead assertions (conditions):
^(?=.*?[A-Z])(?=.*?[a-z])(?=.*?[0-9])(?=.*?[#?!@$%^&*-]).{8,}$
This regex will enforce these rules:
- At least one upper case English letter,
(?=.*?[A-Z]) - At least one lower case English letter,
(?=.*?[a-z]) - At least one digit,
(?=.*?[0-9]) - At least one special character,
(?=.*?[#?!@$%^&*-]) - Minimum eight in length
.{8,}(with the anchors)
Solution 3:
Regular expressions don't have an AND operator, so it's pretty hard to write a regex that matches valid passwords, when validity is defined by something AND something else AND something else...
But, regular expressions do have an OR operator, so just apply DeMorgan's theorem, and write a regex that matches invalid passwords:
Anything with less than eight characters OR anything with no numbers OR anything with no uppercase OR or anything with no lowercase OR anything with no special characters.
So:
^(.{0,7}|[^0-9]*|[^A-Z]*|[^a-z]*|[a-zA-Z0-9]*)$
If anything matches that, then it's an invalid password.