How do you cache a variable in jQuery?

Question

If I'm constantly referencing:

$('#' + n + ':nth-child(2)').val()

then how do I cache $('#' + n) into a variable?

$n = $('#' + n);
$n:nth-child(2)

Answer 1

You need to use .filter(), which applies the selector to elements at the root of the jQuery object instead of .find() or the context parameter, which search inside the elements at the root.

var $n = $('#' + n);
var second = $n.filter(':nth-child(2)');

That is assuming that the initial selector in your question evaluates to something like:

$('#someID:nth-child(2)')

If it is, it would concern me a little since there should only be one element with someID.

To give a more certain answer, we would need to know the value of n.

Answer 2

Another way:

$n = $('#' + n);
$n.find(":nth-child(2)");

Answer 3

Try this:

var $n = $('#' + n); 
var $child = $(":nth-child(2)", $n);