CODEWITHSUNDEEP
iosswiftuitextfield
NTaveras
NTaveras

Reputation: 83

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

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?

Upvotes: 0

Views: 1538

Answers (5)

islam XDeveloper
islam XDeveloper

Reputation: 500

it's best solution for guard if you have value int

  guard (shippingID != 0 )  else {
            ShowAlerts.displayMessage(message: "Error".localized, body: "Select the Shipping Type".localized, messageError: true)
            return
        }

Upvotes: 0

Dancreek
Dancreek

Reputation: 9544

It would be better to validate as they type. You should implement a UITextFieldDelegate. And then implement this in your delegate:

    func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {
          //Check for illegal characters
          return (string.rangeOfCharacter(from: CharacterSet(charactersIn: "0123456789").inverted) == nil)
        }

This prevents any illegal entry from happening in the first place.

Upvotes: 0

Sulthan
Sulthan

Reputation: 130152

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       
}

Upvotes: 1

Dharmesh Kheni
Dharmesh Kheni

Reputation: 71852

Here is the way you can achieve it:

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

Upvotes: 0

Code Different
Code Different

Reputation: 93191

It's easier if you use guard let:

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

// Do something with your level

Upvotes: 0

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