jquery Learning-sub-selectors and visibility selectors

<! DOCTYPE html>"UTF-8"> <title> Sub-selector and visibility selector </title> <script src="Js/jquery.js"></script> <script type="Text/javascript">$ (function () {//The Li that appears in the first position of its parent element$("Li:first-child"). CSS ("Border","2px solid Red")                 //The Li that appears at the last position of its parent element$("Li:last-child"). CSS ("Border","2px Solid Orange")                   //Li, who appears in the third position of its parent element, learned before 1: EQ (n) starts at 0,$("Li:nth-child (3)"). CSS ("Border","2px solid Blue")                   //get all the elements that can be displayed$(": Visible"). CSS ("Border","2px solid Blue")                  })        //</script> 1</li> <li>2</li> <li>3</li> <li>4</li> <li>5</li> <li>6</li> <ul> <li>7</li> <li>8</li> </ul> </ul> </div> </body>
jquery Learning-sub-selectors and visibility selectors