Possible way to detect sim card detection in ios?

Question

I have a iphone app that has the capability to send messages. I want to alert user when sim card is not available in iphone. So i tried below three function to check sim car

Answer 1

Implemented in Swift as a read-only computed property:

import CoreTelephony

var availableSIM: Bool {
    return CTTelephonyNetworkInfo().subscriberCellularProvider?.mobileNetworkCode != nil
}