javascript - How to I get (this) parents child using Jquery -

example:

<div id="parent">   <div id="child"></div> </div> 

we know when want value of parent's child can use selector ("#parent #child"). however, how can child using method. (this+'#child') not job.

well!! if using id selector don't need use context id supposed unique... $('#child') otherwise yes $('childselector', this)