jQueryのフィルタセレクタ

    <span style="color: #000000;">

        $(</span><span style="color: #0000ff;">function</span><span style="color: #000000;">(){
            $(</span>"ul li:first").css("color","yellow"<span style="color: #000000;">);
            $(</span>"ul li:last").css("color","pink"<span style="color: #000000;">);
            $(</span>"ul li:odd").css("color","blue"<span style="color: #000000;">);
        })
        
        </span><span style="color: #008000;">//</span><span style="color: #008000;"> :first          </span>
        <span style="color: #008000;">//</span><span style="color: #008000;"> :last            </span>
        <span style="color: #008000;">//</span><span style="color: #008000;"> :eq(index)      </span>
        <span style="color: #008000;">//</span><span style="color: #008000;"> :odd           </span>
        <span style="color: #008000;">//</span><span style="color: #008000;"> :even          </span>
        
        <span style="color: #008000;">//</span><span style="color: #008000;"> jquery  ul     li</span>
        console.log($("ul li:first").css("color","blue"<span style="color: #000000;">));
        $(</span>"ul li").eq(0<span style="color: #000000;">);
        $(</span>"ul li"<span style="color: #000000;">).first();
        $(</span>"ul li").slice(0,1);<span style="color: #008000;">//</span><span style="color: #008000;">slice               ，           </span>
        <span style="color: #008000;">//</span><span style="color: #008000;">   </span>
        $(<span style="color: #0000ff;">function</span><span style="color: #000000;">(){
            </span><span style="color: #0000ff;">var</span> list=$("ul"<span style="color: #000000;">);
            </span><span style="color: #0000ff;">for</span> (<span style="color: #0000ff;">var</span> i = 0; i < list.length; i++<span style="color: #000000;">) {
                $(</span>"ul:eq("+i+") li:first").css("background","red"<span style="color: #000000;">);
            
            }
        });
        </span><span style="color: #008000;">//</span><span style="color: #008000;">    </span>
        $(<span style="color: #0000ff;">function</span><span style="color: #000000;">(){
            $(</span>"ul").each(<span style="color: #0000ff;">function</span><span style="color: #000000;">(){
                $(</span><span style="color: #0000ff;">this</span>).children().first().css("background","red"<span style="color: #000000;">); 
            });
        });
        </span><span style="color: #008000;">//</span><span style="color: #008000;">   </span>
        $(<span style="color: #0000ff;">function</span><span style="color: #000000;">(){
            $(</span>"ul li:nth-child(1)").css("background","red"<span style="color: #000000;">);
        });
        </span><span style="color: #008000;">//</span><span style="color: #008000;">   </span>
        $(<span style="color: #0000ff;">function</span><span style="color: #000000;">(){
            $(</span>"ul li:first-child").css("background","red"<span style="color: #000000;">);
        });
    </span>