Uppercase characters in UItextfield

Question

I have a question about iOS UIKeyboard.

I have a UITextField and I would to have the keyboard with only uppercase characters.<

Answer 1

/**
 We take full control of the text entered so that lowercase cannot be inserted
 we replace lowercase to uppercase
*/
func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {

    // No spaces allowed
    if string == " " {
        return false
    }

    // delete key pressed
    if string == "" {
        textField.deleteBackward()
        return false
    }

    // We only allow alphabet and numbers
    let numbersAndLettersSet = CharacterSet.alphanumerics
    if string.lowercased().rangeOfCharacter(from: numbersAndLettersSet) == nil {
        return false
    }

    // Add the entered text
    textField.insertText(string.uppercased())

    // Return false as we are doing full control
    return false
}