Regular Expression In Android for Password Field

Question

How can i validating the EditText with Regex by allowing particular characters . My condition is :

Password Rule:

1. On

Answer 1

None of the above worked for me.

What worked for me:

fun isValidPasswordFormat(password: String): Boolean {
    val passwordREGEX = Pattern.compile("^" +
        "(?=.*[0-9])" +         //at least 1 digit
        "(?=.*[a-z])" +         //at least 1 lower case letter
        "(?=.*[A-Z])" +         //at least 1 upper case letter
        "(?=.*[a-zA-Z])" +      //any letter
        "(?=.*[@#$%^&+=])" +    //at least 1 special character
        "(?=\\S+$)" +           //no white spaces
        ".{8,}" +               //at least 8 characters
        "$");
    return passwordREGEX.matcher(password).matches()
}

Source: Coding in Flow

Hope it helps someone.

Answer 2

And for the Kotlin lovers :

fun isValidPassword(password: String?) : Boolean {
   password?.let {
       val passwordPattern = "^(?=.*[0-9])(?=.*[a-z])(?=.*[A-Z])(?=.*[@#$%^&+=])(?=\\S+$).{4,}$"
       val passwordMatcher = Regex(passwordPattern)

       return passwordMatcher.find(password) != null
   } ?: return false
}

Answer 3

Most common password validation is

1. At least 8 character
2. Require numbers
3. Require special character
4. Require uppercase letters
5. Require lowercase letters

Regex:

^(?=.*[0-9])(?=.*[a-z])(?=.*[A-Z])(?=.*[\\\/%§"&“|`´}{°><:.;#')(@_$"!?*=^-]).{8,}$

Kotlin code:

    val PASSWORD_REGEX_PATTERN = "^(?=.*[0-9])(?=.*[a-z])(?=.*[A-Z])(?=.*[\\\/%§"&“|`´}{°><:.;#')(@_$"!?*=^-]).{8,}$"

    fun isValidPassword(password: String?): Boolean {
        val pattern: Pattern =
            Pattern.compile(PASSWORD_REGEX_PATTERN)
        val matcher: Matcher = pattern.matcher(password)
        return matcher.matches()
    }

online regex validator to check it:

• https://regex101.com/
• https://www.freeformatter.com/java-regex-tester.html#ad-output

Answer 4

try {
    if (subjectString.matches("^(?=.*[@$%&#_()=+?»«<>£§€{}\\[\\]-])(?=.*[A-Z])(?=.*[a-z])(?=.*\\d).*(?<=.{4,})$")) {
        // String matched entirely
    } else {
        // Match attempt failed
    } 
} catch (PatternSyntaxException ex) {
    // Syntax error in the regular expression
}


(?=.*[@\$%&#_()=+?»«<>£§€{}.[\]-]) -> must have at least 1 special character
(?=.*[A-Z])   -> Must have at least 1 upper case letter
(?=.*[a-z])   -> Must have at least 1 lower case letter
(?=.*\\d)     -> Must have at least 1 digit
(?<=.{4,})$") -> Must be equal or superior to 4 chars.