How should I validate an e-mail address?

Question

What\'s a good technique for validating an e-mail address (e.g. from a user input field) in Android? org.apache.commons.validator.routines.EmailValidator doesn\'t seem to be

Answer 1

Simplest Kotlin solution using extension functions:

fun String.isEmailValid() =
            Pattern.compile(
                    "[a-zA-Z0-9\\+\\.\\_\\%\\-\\+]{1,256}" +
                            "\\@" +
                            "[a-zA-Z0-9][a-zA-Z0-9\\-]{0,64}" +
                            "(" +
                            "\\." +
                            "[a-zA-Z0-9][a-zA-Z0-9\\-]{0,25}" +
                            ")+"
            ).matcher(this).matches()

and then you can validate like this:

"testemail6589@gmail.com".isEmailValid()

If you are in kotlin-multiplatform without access to Pattern, this is the equivalent:

fun String.isValidEmail() = Regex(emailRegexStr).matches(this)