Extension functions allow you to add new functionality to existing classes without modifying their code. This is particularly useful for adding utility methods to standard library classes or third-party libraries, making your code cleaner and more expressive. By using extension functions, you can enhance readability and maintainability while keeping your code organized.
fun String.isEmailValid(): Boolean { return android.util.Patterns.EMAIL_ADDRESS.matcher(this).matches() } // Usage val email = "example@example.com" if (email.isEmailValid()) { println("The email is valid.") } else { println("The email is invalid.") }