问：怎么用js将123数字分割输出为<em>1</em><em>2</em><em>3</em>？求完整代码？

答：

<!DOCTYPE html>
<html>
    <head>
        <meta charset="utf-8">
        <title>测试</title>
    </head>
    <body>
        <script type="text/javascript">
            document.write("<em>" + "123".toString().split("").join("</em><em>") + "</em>");
        </script>
    </body>
<html>