熟悉JS中的常用选择器及属性、方法的调用

2022-12-08 23:04:48

选择器、属性及方法调用的配合使用：

<style>
            #a{
                width: 200px;
                height: 100px;
                background-color: red;

            }
            .b{
                width: 200px;
                height: 100px;
                background-color: green;

            }
            .div1{
                width: 200px;
                height: 100px;
                background-color:aqua;
            }
        </style>

    <body>
        <div id="a"></div>
        <div class="b" style="background-color: black;"></div>
        <div class="b" style="background-color: chartreuse;"></div>
        <div class="div1">精英教育</div>
        <input type="text" name="ipt1" />
        <input type="checkbox" name="ckb2" / disabled="disabled">
    </body>

    <script>
        //先选择元素在进行加效果
        //ID选择器(使用较高JS)
        var a = document.getElementById("a");
        //检测类型
        alert(typeof(document.getElementById("a")))

        a.style.backgroundColor="royalblue";

        a.innerHTML ="<span>hello<span>";
        a.innerText = "<span>hello<span>";
//        class选择器
        var b_class = document.getElementsByClassName("b");
        b_class[0].style.backgroundColor="red";

        var b_class = document.getElementsByClassName("b");
        b_class[1].style.backgroundColor="blueviolet";
//        标签选择器
        var b_b = document.getElementsByTagName("div");
        b_b[1].style.backgroundColor="yellow";

        var div_1 = document.getElementsByName("ipt1");
        div_1[0].value="文本框";

        var ckb2 = document.getElementsByName("ckb2")[0];
        ckb2.setAttribute("checked","");
    //移除属性
        ckb2.removeAttribute("disabled")

    //创造元素
    var a = document.createElement("a");
    a.setAttribute("href","http://www.baidu.com");
    a.innerText="百度一下";

    document.body.appendChild(a);
    document.body.removeChild(a);

    div1.appendChild(a);


    </script>

<body>
       
       <div id="div1" class="div1"></div>
       <div class="div1"></div>
       <input type="text" name="ipt1" />
       <input type="checkbox" name="ckb1" disabled="disabled"/>
   </body>
</html>
<script>
//   alert('1111');
//   window.alert('123')
   var div1 = document.getElementById('div1');
   div1.style.backgroundColor = 'red';
//   div1.innerHTML = "<ul><li>123456</li></ul>";
   div1.innerText = "<ul><li>123456</li></ul>";


   var div1_class = document.getElementsByClassName('div1');
   div1_class[1].style.backgroundColor = "green";

   var div1_1 = document.getElementsByTagName('div');
   div1_1[1].style.backgroundColor = "blue";

//   jQuery
   var div1_2 = document.getElementsByName('ipt1');
   div1_2[0].value = '123';

   var ckb1 = document.getElementsByName('ckb1')[0];
//   ckb1.setAttribute("checked","checked");
   ckb1.removeAttribute('disabled');

   var a = document.createElement("a");
   a.setAttribute("href","http://www.baidu.com");
   a.innerText = "百度";

   document.body.appendChild(a);
   document.body.removeChild(a);

   div1.appendChild(a);
</script>