Check Valid Password

password.swift

func isValidPassword(password: String) -> Bool {
    // define validation rules here
    let passwordRegEx = "(?=.*[A-Z])(?=.*[0-9])(?=.*[a-z]).{8,}"
    let passwordPred = NSPredicate(format: "SELF MATCHES %@", passwordRegEx)
    return passwordPred.evaluate(with: password)
}

How to use the isValidPassword(password:) function:

Example Usage:

1. Checking Password Validity:

   let password = "MyPassword123"
   if isValidPassword(password: password) {
       print("Valid password")
   } else {
       print("Invalid password")
   }

2. Validating User Input:

   let passwordTextField = UITextField()
   passwordTextField.addTarget(self, action: #selector(textFieldDidChange(_:)), for: .editingChanged)
   
   @objc func textFieldDidChange(_ textField: UITextField) {
       if isValidPassword(password: textField.text ?? "") {
           textField.layer.borderColor = UIColor.green.cgColor
       } else {
           textField.layer.borderColor = UIColor.red.cgColor
       }
   }

3. Displaying a Password Strength Indicator:

   let password = "MyPassword123"
   let strength = isValidPassword(password: password) ? "Strong" : "Weak"
   print("Password strength: \(strength)")

Explanation:

• The isValidPassword(password:) function checks if a password meets certain validation rules, such as containing at least one uppercase letter, one lowercase letter, one digit, and being at least 8 characters long.
• You can use the function to validate user input and provide feedback on password strength or validity.
• In the example, the function is used to check the validity of a password entered in a text field, and to display a border color based on the password's validity.
• The function can also be used to display a password strength indicator, such as "Strong", "Medium", or "Weak", based on the complexity of the password.

By using the isValidPassword(password:) function, you can ensure that passwords entered by users meet certain security requirements, and provide feedback on password strength or validity.