Question

I would really like to know what the following jquery line of code does:

$('input', f).add('textarea', f).add('select', f).change(enable).one('blur', function () {

 //commands go here

});

Can somebody please explain to me the first line of code ?

Answer 1

That line takes every input, textarea, and select element within some other jQuery object, f, and binds a change event handler, which is some function called enable. Then, it hooks up an event to the onblur method of those objects that only gets executed at most one time.

The line:

$('input', f).add('textarea', f).add('select', f)

Is really just equivalent to:

$('input, textarea, select', f)

Which selects the union of all of those elements within some context, f. Then, check out the documentation for change() and one() for the full explanation.