Javascript验证错误,无法提交表单

Javascript Validation error, can't submit the form

本文关键字:提交 表单 验证 错误 Javascript      更新时间:2023-09-26

我正在做这个项目,我在HTML中做了一个注册表格,并通过javascript验证了它'简单'。通过"简单",我的意思是我只是确保输入字段不是空的。现在,问题是什么?一切都很好,直到有人从大学列表(id=cname)中选择"其他人"选项,并出现一个新的输入框(其中id=cname1)。现在,如果有人将输入框保留为空,它将返回一个警告:"学院名称不能为空!"’,但是他无法点击提交按钮。我仔细检查了语法,一切似乎都没问题。下面是我的javascript代码:

            function validate(){
                var name=document.getElementById("name").value;
                if(name===""){
                      document.getElementById("ename").innerHTML="Please Enter a Name";
                      return false;
                }else{
                    var mail=document.getElementById("mail").value;
                    if(mail===""){
                      document.getElementById("email").innerHTML="Please Enter an Email";
                      return false;
                    }else{
                    var num=document.getElementById("num").value;
                    if(num===""){
                      document.getElementById("enum").innerHTML="Please Enter Phone number";
                      return false;
                    }else{
                       var batch=document.getElementById("batch").value;
                       if(batch===""){
                            document.getElementById("ebatch").innerHTML="Please Enter a Batch";
                            return false;
                        }
                        else{
                            var cname=document.getElementById("cname").value;
                            if(cname===""){
                            document.getElementById("ecname").innerHTML="Please Enter a College Name";
                            return false;
                            }else if(cname==="others"){
                                var cname1=document.getElementById("cname1").value;
                                if(cname1==="")
                                    alert("College Name can't be empty");
                                return false;
                            }else{
                                var activity=document.getElementById("activity").value;
                                if(activity===""){
                                document.getElementById("eactivity").innerHTML="Please Enter a Activity Name";
                                return false;
                                }else{
                                    return true;
                                 }
                            }
                        }
                    }
                }
            }
        }
    

更新2:缩小的HTML

<tbody>
            <tr>
                <td>Name</td>
                <td><input class="css-input" type="text" id="name" name="name" placeholder="Enter your name"></td>
                <td><p id="ename"></p></td>
            </tr>
            <tr>
                <td>Email</td>
                <td><input class="css-input" type="text" id="mail" name="mail" placeholder="Enter your Email Id"></td>
                <td><p id="email"></p></td>
            </tr>
            <tr>
                <td>Phone</td>
                <td><input class="css-input" type="tel" id="num" name="num" Placeholder="Phone Number"></td>
                <td><p id="enum"></p></td>
            </tr>
            <tr>
                <td>Course</td>
                <td>
                    <select class="css-input" name="course"  id="course">
                        <option value="mbbs" >MBBS</option>
                        <option value="bds" selected="selected" >BDS</option>
                    </select>
                </td>
            </tr>
            
            <tr>
                <td>Batch</td>
                <td>
                    <select class="css-input" name="batch" id="batch" >
                        <option value="10">2010</option>
                        <option value="11">2011</option>
                        <option value="12">2012</option>
                        <option value="13">2013</option>
                        <option value="14">2014</option>
                        <option value="15">2015</option>
                    </select>
                </td>
                <td><p id="ebatch"></p></td>
            </tr>
            <tr>
                <td>WorkShop</td>
                <td  id="first">
                    <select class="css-input" name="workshop1">
                        <option value="dentistry">Dentistry</option>
                        <option value="communicationsoftskill">Communication and Soft Skills</option>
                        <option value="research">Going about Research</option>
                        <option value="None">None</option>
                    </select>
                        
                </td><td  id="third">
                    <select class="css-input" name="workshop3">
                       
                        <option value="communicationsoftskill">Communication and Soft Skills</option>
                        <option value="research">Going about Research</option>
                        <option value="None">None</option>
                    </select>
                        
                </td>
                 <td class="second" id="second">
                    <select class="css-input" name="workshop2">
                        <option value="surgery">Surgical</option>
                        <option value="radiodiagnostic">Radiodiagnostics</option>
                        <option value="comandsoftskill">communication and soft skills</option>
                        <option value="emercriticalcare">emergency and critical care</option>
                        <option value="research">going about research</option>
                        <option value="None">None</option>
                    </select>
                </td>
            </tr>
            
            <tr>
                <td>College name</td>
                <td>
                    <select class="css-input" name="cname" id="cname">
                        <option value="PGIMS, Rohtak">PGIMS, Rohtak</option>
                        <option value="Swami Devi Dayal Dental College , Panchkula">Swami Devi Dayal Dental College , Panchkula</option>
                        <option value="BRS Instititute of Medical Sciences Dental College and Hospital , Sultanpur , Panchkula">BRS Instititute of Medical Sciences Dental College and Hospital , Sultanpur , Panchkula</option>
                        <option value="Kothiwal Dental and Research Centre , Moradabad">Kothiwal Dental and Research Centre , Moradabad</option>
                        <option value="Teerthankar Mahavir Dental College , Moradabad">Teerthankar Mahavir Dental College , Moradabad</option>
                        <option value="Teerthankar Mahavir Medical College and Research Center , Moradabad">Teerthankar Mahavir Medical College and Research Center , Moradabad</option>
                        <option value="ESIC , Faridabad">ESIC , Faridabad</option>
                        <option value="Maharishi Markandeshwar College of Dental Sciences , Mullana , Ambala">Maharishi Markandeshwar College of Dental Sciences , Mullana , Ambala</option>
                        <option value="JN Kapoor DAV Centenary Dental College and Hospital , Yamunanagar">JN Kapoor DAV Centenary Dental College and Hospital , Yamunanagar</option>
                        <option value="Jan Nayak Ch. Devi Lal Dental College , Sirsa">Jan Nayak Ch. Devi Lal Dental College , Sirsa</option>
                        <option value="Manav Rachna Dental College , Faridabad">Manav Rachna Dental College , Faridabad</option>
                        <option value="SGT Dental College , Gurgaon">SGT Dental College , Gurgaon</option>
                        <option value="PDM Dental College and Research Institute , Bahadurgarh">PDM Dental College and Research Institute , Bahadurgarh</option>
                        <option value="Sudha Rustagi College of Dental Sciences And Research , Faridabad">Sudha Rustagi College of Dental Sciences And Research , Faridabad</option>
                        <option value="Dr. Harvansh Singh Gudge Institute of Dental Sciences and Hospital , Chandigarh">Dr. Harvansh Singh Gudge Institute of Dental Sciences and Hospital , Chandigarh</option>
                        <option value="Swami Devi Dayal Hospital and Dental College, Barwala">Swami Devi Dayal Hospital and Dental College, Barwala</option>
                        <option value="Yamuna Institute of Dental Sciences And Research , Yamunanagar">Yamuna Institute of Dental Sciences And Research , Yamunanagar</option>
                        <option value="Lala Lajpat Rai Memorial Medical College , Meerut , Uttar Pradesh">Lala Lajpat Rai Memorial Medical College , Meerut , Uttar Pradesh</option>
                        <option value="Dayanand Medical College , Ludhiana">Dayanand Medical College , Ludhiana</option>
                        <option value="CMC , Ludhiana">CMC , Ludhiana</option>
                        <option value="GMC , Chandigarh">GMC , Chandigarh</option>
                        <option value="AFMC , Pune">AFMC , Pune</option>
                        <option value="ACMS , Delhi Cantt.">ACMS , Delhi Cantt.</option>
                        <option value="UCMS , New Delhi">UCMS , New Delhi</option>
                        <option value="VMMC , New Delhi">VMMC , New Delhi</option>
                        <option value="Sawai Man Singh Medical College , Jaipur">Sawai Man Singh Medical College , Jaipur</option>
                        <option value="IGMC , Shimla ">IGMC , Shimla </option>
                        <option value="Gold Institute of Medical Sciences and Research , Ballabhgarh ">Gold Institute of Medical Sciences and Research , Ballabhgarh </option>
                        <option value="28.  Maharshi Markandeshwar Institute of Medical Sciences and Research , Mullana , Ambala">Maharshi Markandeshwar Institute of Medical Sciences and Research , Mullana , Ambala</option>
                        <option value="SGT Medical College , Budhera , Gurgaon">SGT Medical College , Budhera , Gurgaon</option>
                        <option value="Maharaja Agarsen Medical College , Agroha , Hisar">Maharaja Agarsen Medical College , Agroha , Hisar</option>
                        <option value="Shaheed Hasan Khan Mewati GMC , Mewat ">Shaheed Hasan Khan Mewati GMC , Mewat </option>
                        <option value="BPS GMC for women , Khanpur">BPS GMC for women , Khanpur32.  BPS GMC for women , Khanpur</option>
                        <option value="GMC , Patiala ">GMC , Patiala </option>
                        <option value="others">others</option>
                    </select>
                </td>
                <td><input class="css-input" type="text" name="cname1" id="cname1" placeholder="enter Your college name"></td>
	<input type="hidden" value="1" id="flg" name="flg">
                <td><p id="ecname"></p></td>
            </tr>
            
            <tr>
                <td>Accomodation</td>
                <td>
                    <select class="css-input" id="accom" name="accom">
                        <option value="yes" selected="selected">YES</option>
                        <option value="no">NO</option>
                    </select>
                </td>
            </tr>
            <tr>
                <td><input class="css-input" type="reset"></td>
                <td><input style="cursor: pointer;" class="css-input" type="submit" ></td>
            </tr>
        </tbody>

谢谢

问题是你没有把if语句用大括号括起来。

违规代码段:

var cname1=document.getElementById("cname1").value;
if(cname1==="")
   alert("College Name can't be empty");
return false;

这就相当于这样写:

var cname1=document.getElementById("cname1").value;
if(cname1==="") {
   alert("College Name can't be empty");
}
return false;

这意味着一旦您得到这个值,您将始终返回false。这将始终阻止表单提交,只要用户执行到这里。

修复方法很简单:

var cname1=document.getElementById("cname1").value;
if(cname1==="") {
   alert("College Name can't be empty");
   return false;
}
由于这个原因,许多人认为在编写JavaScript时总是包含大括号是最佳实践。