select last 5 elements from an element collection using :gt() selector

Question

Consider that, i had selected all tr elements from a table which contains 10 rows, now from that i just tried to filter out the last 5 elements by using the following way

var xTrs = $('tr');
var xLastTrs = xTrs.filter(':gt('+ (xTrs.length - 6) +')');

Now the above snippet is working fine when i am having more than 5 rows in that table, but when the scenario becomes like, the table is having only 5 rows, the selector get validated as xTrs.filter(':gt(-1)'); and it is refusing to fetch the expected result.

what i am doing wrong here..? I thought :gt(-1) would select all the elements which is having index from 0 to 4 in that context. Please correct me if i am thinking in a wrong way.

And by the way, first tell me how can we achieve that by using :gt() and after that let me know some other efficient ways.

Answer 1

:gt supports negative indices

negative index: Zero-based index, counting backwards from the last element.

var xTrs = $('tr');
var xLastTrs = xTrs.filter(':gt(-5)');

so does slice

var xLastTrs = xTrs.slice(-5);

Answer 2

Test if xTrs.length is more than 5 before filtering:

xLastTrs = (xTrs.length <= 5) ? xTrs ? xTrs.filter(':gt('+ (xTrs.length - 6) +')');

Answer 3

Try,

var xTrs = $('tr');
var xLen = xTrs.length - 5;
var xLastTrs = xTrs.filter(':eq('+ xLen +'),:gt(' + xLen + ')');

Clever isn't.?