JQ Selector _ Select the implementation method of the nth child element of the similar element _jquery

Before you want to select all the UL in the nth Li, so write: $ (' ul li:eq (N-1) '), it is the result of the selection of all the UL below the results of the nth elements, this thinking is wrong (because looked very pleasing: Select all the ul below the nth Li, in my Mind $ ( ' UL Li:eq (N-1) ') has been separated by me, if only the official could make this kind of chain-style writing. For example: $ (' ul '). $ (' Li:eq (N-1) '), it seems that this writing will have to wait for me to learn more things to write a framework,

Now that I'm confused, I suddenly feel that the selector is a very advanced kind of thing.

Since it is not possible to select at the same time to use the traversal on the line, the following is an example, as for traversal of the writing a lot of their favorite.

Paste code (select the third Li in each UL inside):

<! DOCTYPE html>
 
 

The above JQ selector _ Select the same elements of the nth element of the implementation method is small series to share all the content, hope to give you a reference, but also hope that we support the cloud habitat community.