Javascript – How to extend jQuery to make it easier to retrieve the tagName

javascriptjquery

I am looking to extend jQuery so I can easily retrieve the tagName of the first element in a jQuery object. This is what I have come up with, but it doesn't seem to work:

$.fn.tagName = function() {
    return this.each(function() {
        return this.tagName;
    });
}
alert($('#testElement').tagName());

Any ideas what's wrong?

BTW, I'm looking to use this more for testing than in production.

Best Answer

Try this instead:

$.fn.tagName = function() {
    return this.get(0).tagName;
}
alert($('#testElement').tagName());

To explain a little bit more of why your original example didn't work, the each() method will always return the original jQuery object (unless the jQuery object itself was modified). To see what is happening in each with your code, here is some pseudocode that shows how the each() method works:

function each(action) {
    for(var e in jQueryElements) {
        action();
    }
    return jQueryObject;
}

This is not how each() really gets implemented (by a long shot probably), but it is to show that the return value of your action() function is ignored.

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