前端面试题

前端面试题（html&javascript)：

<!DOCTYPE html>
<html>
    <head>
        <meta charset="UTF-8">
        <title></title>
    </head>
    <body>
        <style type="text/css">
            .sty1{
                color: red;
            }
        </style>
        
        <form method="get" onsubmit="func3()">
            用户名:<input type="text" name="username" id="uname" value="" onfocus="func1()" onblur="func2()" />
            <span id="p1"></span>
            <br/>
            密码:<input type="password" name="password" id="pwd" value="" />
            <br />
            确认密码:<input type="password" id="pwd2" value="" />
            <br />
            <input type="submit" value="提交"/>
        </form>
        
        
            
        <script type="text/javascript">
            function func1(){
                var sp1 = document.getElementById("p1").innerHTML = "用户名必须是字母或者下划线";
                document.getElementById("p1").className = "sty1";
                
            }
            
            function func2(){
                var sp1 = document.getElementById("p1").innerHTML = "";
            }
            
            function func3(){
                // 书写正则表达式
                var re = /^[a-zA-Z0-9_]+$/;
                // 验证是否密码符合上面正则表达式
                var flag = re.test(document.getElementById("pwd").value);
                if(flag){
                    return true;
                }else{
                    
                    return false;                
                }
            }
        </script>
        
        
    </body>
</html>

 

posted @ 2018-12-13 23:25  zhangqi0828  阅读(105)  评论(0)  编辑  收藏  举报