Question

In jQuery is there a way to throw/return no elements if jQuery selector returns more than one DOM element? I know you can wrap every call with a simple check, but I’d like to use an existing method if any.

Answer 1

There’s no built-in method, but it wouldn’t be hard to add one:

(function($) {
    $.fn.oneOnly = function() {
        if (this.length === 1) {
            return this;
        } else {
            return $();  // or throw / $.error()
        }
    };
 })(jQuery);

Put it in a chain to null out the chain if more than one element matched:

 $(sel).oneOnly().doSomething();

See http://jsfiddle.net/alnitak/sevTY/