https://www.archie.tw/?p=227&preview=true

ViewController.swift

class ViewController: UIViewController {
    @IBOutlet private weak var nameTextField: UITextField! {
        didSet {
            nameTextField.placeholder = "給值"
        }
    }
    @IBOutlet private weak var passwordTextField: UITextField! {
        didSet {
            passwordTextField.placeholder = "給值"
        }
    }
    @IBOutlet private weak var addressTextField: UITextField! {
        didSet {
            addressTextField.placeholder = "給值"
        }
    }
}