How to get the object's id?

Question

How to get the id on an object, i know the id is hola, but i need to get it during runtime

alert($('#hola').id);

The idea is this:

<script>

    (function ($) {

    $.fn.hello = function(msg) {
        alert('message ' + msg);
        alert('is from ' + this.id); // this.id doesn't work
    };

    })(jQuery);


    $('#hola').hello('yo');

</script>

Answer 1

Use attr() to read attributes:

alert($('#hola').attr('id'));

Answer 2

The most efficient approach would be:

this[0].id

this.attr("id") takes longer to achieve the same thing because many checks are made and different codepaths are followed based on the parameter passed. Depending on how often you call the function, there could be a significant difference on, say, a mobile browser with a slow processor.

You can read more about this here.