Combining jQuery :not and :nth-child selectors

Question

$j(\'.select-all-these:not(.except-these):nth-child(3n)\');

I\'m trying to select every third item that doesn\'t have a particular class. This is m

Answer 1

UPDATE: i don't think this is possible with nth-child or another selector of jQuery. so consider using a more verbose solution:

var count = 0;
$('.select-all-these').each(function() {
    if(!$(this).hasClass('except-these')) {
        count++;
    }
    if(count === 3) {
        $(this).text('every 3rd element');
        count = 0
    }
});​

http://jsfiddle.net/TJdFS/2/ (alternative version: http://jsfiddle.net/TJdFS/)

:nth-child counts all matching elements ignoring any additional filters like :not.

see jquery doc:

The :nth-child(n) pseudo-class is easily confused with :eq(n), even though the two can result in dramatically different matched elements. With :nth-child(n), all children are counted, regardless of what they are, and the specified element is selected only if it matches the selector attached to the pseudo-class. With :eq(n) only the selector attached to the pseudo-class is counted, not limited to children of any other element, and the (n+1)th one (n is 0-based) is selected.

Example:

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6

JS:

$('.select-all-these:not(.except-these):nth-child(6)').text('nth-child counts all elements (1 based!)');
$('.select-all-these:not(.except-these):eq(1)').text('eq counts only matching elements (0 based!)');

Result:

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3
eq counts only matching elements. (0 based!)
5
nth-child counts all elements (1 based!)

http://jsfiddle.net/nFtkE/2/ ​