Can you provide an example of using the extension pattern?

The extension pattern in Android is often implemented using Kotlin extensions, which allow adding new functions to existing classes without inheritance.

Example of an extension for the String class:

fun String.isEmailValid(): Boolean {
    return android.util.Patterns.EMAIL_ADDRESS.matcher(this).matches()
}

// Usage:
val email = "example@mail.com"
if (email.isEmailValid()) {
    println("Email is valid")
} else {
    println("Email is not valid")
}

This approach improves code readability and makes it convenient to add useful methods to standard classes.