we can handle optional like below. We can explicitly mention all cases along with nil as an additional case. Hope it will be helpful for someone.

switch optionalEnumValue {
 
case .caseOne:
    break
case .caseTwo:
    break
case .caseN:
    break
case nil:
    break
 
}

You can explicitly mention all cases along with nil as an additional case to handle the optional:

switch optionalEnumValue {
case .caseOne:
    break
case .caseTwo:
    break
case .caseN:
    break
case nil:
    break
}

From Swift 5.1 we can handle optional like below. We can explicitly mention all cases along with nil as an additional case. Hope it will be helpful for someone.

switch optionalEnumValue {

case .caseOne:
    break
case .caseTwo:
    break
case .caseN:
    break
case nil:
    break

}

we can handle optional like below. We can explicitly mention all cases along with nil as an additional case. Hope it will be helpful for someone.

switch optionalEnumValue {

case .caseOne:
    break
case .caseTwo:
    break
case .caseN:
    break
case nil:
    break

}