Why doesn't [checked] work as selector in JQUERY?

Question

It seems that the only way to select a checkable input that is actually checked is to use the :checked selector.

Is there a technical reason why this does not work:

$("INPUT[checked]")

whereas it seems to work for other attributes?

Answer 1

Because you would need to put the value for an attribute. But what is it? You write in XHTML checked="checked", in HTML4/5 just plain checked. The DOM model should store it as true.

$('input[checked="checked"]'); // Poor
$('input[checked=true]'); // Maybe

But it is fiddly because of potential browser differences, and checking a boolean, so there is a specific way to do it.

$('input:checked'); // Correct

The internal implementation just checks the elements .checked attribute.

From v1.5.1:

filters: {

    // ...

    checked: function( elem ) {
        return elem.checked === true;
    },

    // ...
}