What is the difference between these two custom event binding methods? Which one is better?

<code>var __onfireEvents = {};

function _bind(eventName, callback, is_one, context) {
    if (typeof eventName !== string_str || typeof callback !== function_str) {
        throw new Error('args: '+string_str+', '+function_str+'');
    }
    if (! hasOwnKey(__onfireEvents, eventName)) {
        __onfireEvents[eventName] = {};
    }
    __onfireEvents[eventName][++__cnt] = [callback, is_one, context];

    return [eventName, __cnt];
}

function on(eventName, callback, context) {
    return _bind(eventName, callback, 0, context);
}
</code>

<code>$customSubMap = {};
subscribeEvent = function ( $collection, event_name, fn ) {
    $collection.on( event_name, fn );
   

    if ( ! $customSubMap[ event_name ] ) {
        $customSubMap[ event_name ] = $collection;
    }
    else {
        $customSubMap[ event_name ]
        = $customSubMap[ event_name ].add( $collection );
    }
};</code>