Password validation in UITextField in iOS

Question

I have 1 UITextfield for password in my iPhone application.

I want to validate this textfield with the following validation.

• Must be at le

Answer 1

You can also do this by using Regex. Here are few example I am providing for you:

// *** Validation for Password ***

    // "^(?=.*[A-Za-z])(?=.*\\d)[A-Za-z\\d]{8,}$" --> (Minimum 8 characters at least 1 Alphabet and 1 Number)
    // "^(?=.*[A-Za-z])(?=.*\\d)(?=.*[$@$!%*#?&])[A-Za-z\\d$@$!%*#?&]{8,16}$" --> (Minimum 8 and Maximum 16 characters at least 1 Alphabet, 1 Number and 1 Special Character)
    // "^(?=.*[a-z])(?=.*[A-Z])(?=.*\\d)[a-zA-Z\\d]{8,}$" --> (Minimum 8 characters at least 1 Uppercase Alphabet, 1 Lowercase Alphabet and 1 Number)
    // "^(?=.*[a-z])(?=.*[A-Z])(?=.*\\d)(?=.*[$@$!%*?&])[A-Za-z\\d$@$!%*?&]{8,}" --> (Minimum 8 characters at least 1 Uppercase Alphabet, 1 Lowercase Alphabet, 1 Number and 1 Special Character)
    // "^(?=.*[a-z])(?=.*[A-Z])(?=.*\\d)(?=.*[$@$!%*?&])[A-Za-z\\d$@$!%*?&]{8,10}" --> (Minimum 8 and Maximum 10 characters at least 1 Uppercase Alphabet, 1 Lowercase Alphabet, 1 Number and 1 Special Character)

Fourth from the list is your case, following code snippet shows how to use it:

-(BOOL)isValidPassword:(NSString *)passwordString
{
    NSString *stricterFilterString = @"^(?=.*[a-z])(?=.*[A-Z])(?=.*\\d)(?=.*[$@$!%*?&])[A-Za-z\\d$@$!%*?&]{10,}";
    NSPredicate *passwordTest = [NSPredicate predicateWithFormat:@"SELF MATCHES %@", stricterFilterString];
    return [passwordTest evaluateWithObject:passwordString];
}

Using the method:

if(![self isValidPassword:txtPassword.text]) {
    /* Show alert: "Password must be minimum 10 characters,
       at least 1 Uppercase Alphabet, 1 Lowercase Alphabet, 
       1 Number and 1 Special Character" */
}
else {
    // Password is valid
}