Checking if textfields are empty Swift

问题

I know there are tons of stack overflow pages out there that explain how to do this but everytime I take the code from here and put it in i get the same error and that error is value of "string?" has no member "text" Any ideas of a solid way that will work for checking if a textfield is empty in swift?

let userEmail = userEmailTextField.text;
// Check for empty fields
if (userEmail.text.isEmpty) {
    // Display alert message
    return;
}

回答1:

This post is given a good answer (it's a pity it has no "accepted" mark). Use (self.field.text?.isEmpty ?? true).

Assume your textField is declared as:

    @IBOutlet weak var textField: UITextField!

You can check its emptiness with:

    if textField.text?.isEmpty ?? true {
        print("textField is empty")
    } else {
        print("textField has some text")
    }

To use the variables in your edited post:

    let userEmail = userEmailTextField.text;
    // Check for empty fields
    if userEmail?.isEmpty ?? true {
        // Display alert message
        return;
    }

or:

    // Check for empty fields
    if userEmailTextField.text?.isEmpty ?? true {
        // Display alert message
        return;
    }

回答2:

The text property is an optional. So it can contains a String or nil.

If you want to treat nil as an empty String then just write

let isEmpty = (textField.text ?? "").isEmpty

回答3:

Alternatively you can also use:

Swift 3:

if (textField.text.characters.count > 0) {
   print("text field not empty")
} else {
   print("text field empty")
}

Swift 4.x and above:

if (textField.text.count > 0) {
       print("text field not empty")
    } else {
       print("text field empty")
    }

回答4:

Give you an example picture and cover code.

@IBAction func save(_ sender: Any) {
    print("Saving...")
    //CHECK MANDATORY FIELDS
    checkMandatoryFields()
}

private func checkMandatoryFields(){

    //CHECK EMPTY FIELDS
    if let type = typeOutle.text, let name = nameOutlet.text, let address = addressOutlet.text, type.isEmpty || name.isEmpty || address.isEmpty {
        print("Mandatory fields are: ")
        errorDisplay(error: "Mandatory fields are: Type, Name, Address.")
        return
    }

    //CHECK SPACE ONLY FIELDS
}

回答5:

Here's the correct answer for this.

textField.text = ""
if (textField.text.isEmpty) {
    print("Ooops, it's empty")
}

回答6:

It was this check that helped me since it was necessary for me to send a request to the API, and it was necessary to send nill instead of "" if the textField is without text.

textField.text!.count > 0  ? textField.text : nil

Alternatively, you can check this way (but this option did not fit me):

if textField.text != nil {

} else {

}

来源：https://stackoverflow.com/questions/38162602/checking-if-textfields-are-empty-swift

标签

swift

textfield