Check if the integer value of a text field is valid in a switch statement [swift]

Question

I've been attempting to check if the integer value of a text field is valid in a switch statement to cover more possible cases rather having long if/elseif statements.

switch characterTextFields {
case Int(characterTextFields[1].text!) == nil:
    validationErrorModal(text: "Level must be a number!")
}

The code above prompts the following error:

Expression pattern of type 'Bool' cannot match values of type '[UITextField]?'

characterTextFields is an array of text fields. I did research about possibly solutions which involved using let and where keywords, but wasn't able to implement correctly. Any suggestions?

Answer 1

You could use switch for that, but you have to switch over that number, not over the input field:

switch Int(characterTextFields[1].text!) {
    case nil:
        validationErrorModal(text: "Level must be a number!")
    case 0?:  // switch over optional value
        break
}

Usually it is simpler to handle the optional first, e.g. :

guard let level = Int(characterTextFields[1].text!) else {
    validationErrorModal(text: "Level must be a number!")
    return
}

and then switch over the non-optional value:

switch level {
   case 0:
     break
   default:
     break       
}