title: how to make text field that to accept only 4 digit or numbers in iphone
body: <p>I have an app in which I want to enter a numeric value in <code>UITextField</code>. But I want to allow only 4 digits to be entered. So <strong>1234</strong> would be valid but <strong>12345</strong> cannot be entered. Any idea how how I can modify this to accept only a numeric value limited to <strong>4</strong> digits?</p>