javascript - 为什么这个代码可以提交过去？-PHP Tutorial-php.cn

javascript - 为什么这个代码可以提交过去？

WBOY

Release： 2016-06-06 20:14:39

Original

951 people have browsed it

一开始我是拿下面这个简短的代码做的实验一开始onsubmit="return false"是这样写的直接return false这样阻止表单提交的这样点击按钮没有任何反应后来我改成函数的形式阻止表单提交就是下面的代码的样子改成这样别人说可以阻止表单提交但是我试的不可以啊点击按钮并不是一点反应没有点击后会有页面刷新而且地址栏的地址也会变后面会多一个? 跟之前直接return false一点不一样第二段代码也是这个情况用onsubmit="return check()" 什么都不填直接点提交也可以提交到数据库里面并不能阻止提交谁知道我的代码哪里有问题呢为什么不能阻止提交？

<code>


    <title></title>
    <script type="text/javascript">
    function check(){
      return false;
    }
</script>


<form onsubmit="return check()">
<input type="submit" value="点击表单不会提交">
</form>

</code>

Copy after login

第二段

<code>


    <meta charset="utf-8">
    <title>
        
    </title>
    <style type="text/css">
    div input{display: inline-block;width: 200px;height: 20px;border:1px solid #ccc;}
    div .span1{display: inline-block;width: 90px;height: 20px;text-align: left;margin-top: 20px;}
    div #sp1,#sp2,#sp3,#sp4{display: inline-block;width: 160px;height: 20px;}
    </style>
    <script src="ajax.js"></script>
    <script type="text/javascript" src="jquery-2.2.2.min.js"></script>
    <script type="text/javascript">
        window.onload=function(){
            var oInput=document.getElementsByTagName('input');
            var oIpt1=document.getElementById('ipt1');
            var oIpt2=document.getElementById('ipt2');
            var oIpt3=document.getElementById('ipt3');
            var oIpt4=document.getElementById('ipt4');
            var oSp1=document.getElementById('sp1');
            var oSp2=document.getElementById('sp2');
            var oSp3=document.getElementById('sp3');
            var oSp4=document.getElementById('sp4');
            var re=/^[\w]{6,12}$/;
            function check(){    
                 return false;       
            };
            oIpt1.onblur=function(){
                if(oIpt1.value==''){
                    this.style.border='1px solid red';
                }else{
                    ajax("nameajax.php?id="+oIpt1.value,function(str){
                    oSp1.innerHTML=str;
                    })
                }
            }; 
            oIpt2.onblur=function(){
               if(oIpt2.value==''){
                   this.style.border='1px solid red';
                   
               }else{
                     if(oIpt2.value.match(re)){
                         oSp2.innerHTML='密码合法';
                     }else{
                         oSp2.innerHTML='密码不合法';
                     }
               }
            }
            oIpt3.onblur=function(){
                if(oIpt3.value==''){
                   this.style.border='1px solid red';
               }else{
                   if(oIpt2.value==oIpt3.value){
                       oSp3.innerHTML='密码正确';
                   }else{
                       oSp3.innerHTML='密码不一致';
                   }
               }
            };
            oIpt4.onblur=function(){
                if(oIpt4.value==''){
                    this.style.border='1px solid red';
                }else{
                    ajax("emailajax.php?id="+oIpt4.value,function(str){
                    oSp4.innerHTML=str;
                    })
                }
                
            }; 
       };
    </script>


<div>
    <form action="reg.php" onsubmit="return check()" method="post">
        <span class="span1">用 户 名:</span><input type="text" id="ipt1" name="username" autocomplete="off"><span id="sp1"></span><br>
        <span class="span1">密　　码:</span><input type="password" id="ipt2" autocomplete="off"><span id="sp2"></span><br>
        <span class="span1">确认密码:</span><input type="password" id="ipt3" name="password" autocomplete="off"><span id="sp3"></span><br>
        <span class="span1">邮　　箱:</span><input type="text" id="ipt4" name="email" autocomplete="off"><span id="sp4"></span><br>
        <button type="submit">提交</button>
    </form>
</div>


</code>

Copy after login

回复内容：

<code>


    <title></title>
    <script type="text/javascript">
    function check(){
      return false;
    }
</script>


<form onsubmit="return check()">
<input type="submit" value="点击表单不会提交">
</form>

</code>

Copy after login

第二段

<code>


    <meta charset="utf-8">
    <title>
        
    </title>
    <style type="text/css">
    div input{display: inline-block;width: 200px;height: 20px;border:1px solid #ccc;}
    div .span1{display: inline-block;width: 90px;height: 20px;text-align: left;margin-top: 20px;}
    div #sp1,#sp2,#sp3,#sp4{display: inline-block;width: 160px;height: 20px;}
    </style>
    <script src="ajax.js"></script>
    <script type="text/javascript" src="jquery-2.2.2.min.js"></script>
    <script type="text/javascript">
        window.onload=function(){
            var oInput=document.getElementsByTagName('input');
            var oIpt1=document.getElementById('ipt1');
            var oIpt2=document.getElementById('ipt2');
            var oIpt3=document.getElementById('ipt3');
            var oIpt4=document.getElementById('ipt4');
            var oSp1=document.getElementById('sp1');
            var oSp2=document.getElementById('sp2');
            var oSp3=document.getElementById('sp3');
            var oSp4=document.getElementById('sp4');
            var re=/^[\w]{6,12}$/;
            function check(){    
                 return false;       
            };
            oIpt1.onblur=function(){
                if(oIpt1.value==''){
                    this.style.border='1px solid red';
                }else{
                    ajax("nameajax.php?id="+oIpt1.value,function(str){
                    oSp1.innerHTML=str;
                    })
                }
            }; 
            oIpt2.onblur=function(){
               if(oIpt2.value==''){
                   this.style.border='1px solid red';
                   
               }else{
                     if(oIpt2.value.match(re)){
                         oSp2.innerHTML='密码合法';
                     }else{
                         oSp2.innerHTML='密码不合法';
                     }
               }
            }
            oIpt3.onblur=function(){
                if(oIpt3.value==''){
                   this.style.border='1px solid red';
               }else{
                   if(oIpt2.value==oIpt3.value){
                       oSp3.innerHTML='密码正确';
                   }else{
                       oSp3.innerHTML='密码不一致';
                   }
               }
            };
            oIpt4.onblur=function(){
                if(oIpt4.value==''){
                    this.style.border='1px solid red';
                }else{
                    ajax("emailajax.php?id="+oIpt4.value,function(str){
                    oSp4.innerHTML=str;
                    })
                }
                
            }; 
       };
    </script>


<div>
    <form action="reg.php" onsubmit="return check()" method="post">
        <span class="span1">用 户 名:</span><input type="text" id="ipt1" name="username" autocomplete="off"><span id="sp1"></span><br>
        <span class="span1">密　　码:</span><input type="password" id="ipt2" autocomplete="off"><span id="sp2"></span><br>
        <span class="span1">确认密码:</span><input type="password" id="ipt3" name="password" autocomplete="off"><span id="sp3"></span><br>
        <span class="span1">邮　　箱:</span><input type="text" id="ipt4" name="email" autocomplete="off"><span id="sp4"></span><br>
        <button type="submit">提交</button>
    </form>
</div>


</code>

Copy after login

<code>function check(){    
     return false;       
 };</code>

Copy after login

这一句不要放在window.onload里边，直接放在外层试试，我试过了可行

加断点跟踪一下吧~
return function中如果代码执行出问题都是按照true来处理的~