<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style type="text/css">
        body {
            font-size: 12px;
        }
        .clsSpn {
            float: left;
            padding-top: 10px;
            padding-left: 10px;
        }
        .clsImg {
            border: 1px solid #cccccc;
            padding: 3px;
            float: left;
        }
    </style>
    <script src="../js/jquery-3.5.1.js"></script>
    <script>
        $(function () {
            $("#btn1").click(function () {
                $('img').attr("src","images/img01.jpg");
                $("img").attr("title","这是一幅风景画");
                $("img").attr({src:"images/img02.jpg",title:"这是另一幅风景画",alt:"这是另一幅风景画"});
                $("img").addClass("clsImg");
                $("span").html("加载完毕");
            });

        })
    </script>
</head>
<body>
    <img alt="" src="images/img02.gif" style="float: left">
    <span class="clsSpn">正在加载图片...</span>
    <input type="button" value="加载" id="btn1">
</body>
</html>