Disable zero as first letter in <input>

Question

Below code disables 0 as the first character in #foo.
However, you can bypass this by typing 123, then drag to select 123

Answer 1

You could add a "submit" event to validate whether it's entered or not, regardless of how it could have gotten there:

$( "form" ).submit(function( event ) {
  if ( $( "input:first" ).val() != 0 ) {
    $( "span" ).text( "Validated..." ).show();
    return;
  }
  $( "span" ).text( "Not valid!" ).show().fadeOut( 1000 );
  event.preventDefault();
});

Type 'Anything but 0' to validate.

  

    
    
  


 

jQuery's working is example is last on page here (https://api.jquery.com/submit/)

NOTE: The most important part will be to add the "event.preventDefault()" action, because that will keep the form from accidentally submitting.