jquery中筛选属性的操作

1.布局和书写一个简单的样式

<ul>
    <li>1</li>
    <li>2</li>
    <li class="li3">3</li>
    <p>31</p>

    <p>32</p>

    <p>33</p>
    <li class="li4">4</li>
    <li><span class="sps">5</span></li>
    <li class="li6"><span class="sp">6</span><span class="sp1">61</span></li>
    <li>7</li>
</ul>
<script src="js/jquery-1.9.1.

 <style>
        body {
            position: fixed;
        }
    </style>

2.筛选 过滤属性

    console.log($("ul>li").eq(0));
    console.log($("ul>li").eq(-1));//注意  倒着找  从-1

    console.log($("ul>li").first());
    console.log($("ul>li").last());
    //直接写名称
    console.log($("ul>li").hasClass("li4"));
    console.log($("ul>li").is(".li4"));

    $("ul>li").each(function (index) {
        if ($(this).hasClass("li4")) {
            console.log($(this));
        }
    });

  console.log($("ul>li").filter(".li4"));
    console.log($("ul>li").filter(function (index) {
        if ($(this).is(".li4")) {
            return $(this);
        }
    }));

    console.log($("ul>li").is(function (index) {
        if ($(this).hasClass("li4")) {
            return true;
        }
    }));

    console.log($("ul>li"));
    console.log($("ul>li").map(function (index, obj) {
        //obj  是原生的js对象
        ;
        return $(obj).text();
    }));


    console.log($("ul>li").has(".sp"));


    console.log($("ul>li").not(".li4"));
    console.log($("ul>li").not($("ul>li").has(".sp")));
    console.log($("ul>li").not(function (index, obj) {
        if ($(obj).is(".li4")) {
            return obj;
        }
    }));


    console.log($("ul>li").slice(0, 2));

3.查找属性

  //children()  不带参 获取元素的所有子集
    console.log($("ul>li").children());
    console.log($("ul>li").children(".sps"));

    console.log($("li:first").parent());
    console.log($("li:first").parents("body"));


    console.log($("ul").find(".li4"));


    console.log($(".li4").next());
    console.log($(".li4").nextAll(".li6"));
    console.log($(".li4").prev());
    console.log($(".li4").prevAll());

    console.log($("ul>li:nth-child(3)").nextUntil(".li4", "p"));
    console.log($("ul>li:nth-child(3)").nextAll());


    console.log($(".li4").offsetParent());

    console.log($(".li4").siblings());
    console.log($(".li4").siblings(".li6"));


    console.log($(".li6").add($(".li3")));

    console.log($(".li6").add("<span>123</span>"));


    console.log($(".li6").nextAll().addBack("li"));


    console.log($(".li6").contents('.sp1'));

    console.log($(".li6").find(".sp1").end());