我们可以检查卷号是否已存在。
使用javascript
我们可以验证这个
显示一条警告消息，表明存在卷号 已经在表格中
window.onload = function() {
document.getElementById('new').style.display = 'none';
};
function addtable(){
document.getElementById('new').style.display = 'block';
Rollno = document.getElementById("roll_number");
Name = document.getElementById("student_name");
Class = document.getElementById("class");
var Gender = null;
var inputElements = document.getElementsByClassName('gender');
for (var i = 0; inputElements[i]; ++i) {
if(inputElements[i].checked){
Gender = inputElements[i].value;
break;
}
};
Age = document.getElementById("age");
Phone = document.getElementById("phone_number");
var Result = null;
var inputElements = document.getElementsByClassName('result');
for(var i=0; inputElements[i]; ++i){
if(inputElements[i].checked){
Result = inputElements[i].value;
break;
}
};
var table = document.getElementById("new");
rowCount = table.rows.length;
row = table.insertRow(rowCount);
row.insertCell(0).innerHTML= Rollno.value;
row.insertCell(1).innerHTML= Name.value;
row.insertCell(2).innerHTML= Class.value;
row.insertCell(3).innerHTML= Gender;
row.insertCell(4).innerHTML= Age.value;
row.insertCell(5).innerHTML= Phone.value;
row.insertCell(6).innerHTML= Result;
row.insertCell(7).innerHTML='<input type="submit" value = "Delete" onclick="deleteRow(this)">';
var roll = document.forms["student_detail"]["roll_number"].value;
if (roll == "") {
alert("Rollno must be filled out");
return false;
}
var name = document.forms["student_detail"]["student_name"].value;
if (name == ""){
alert("Name must be filled out");
return false;
}
var clas = document.forms["student_detail"]["class"].value;
if (clas == "") {
alert("select the class");
return false;
}
var age = document.forms["student_detail"]["age"].value;
if (age == ""){
alert("Age must be filled out");
return false;
}
var phone = document.forms["student_detail"]["phone_number"].value;
if (phone == "") {
alert("Phone number must be filled out");
return false;
}
if (document.student_detail.result1.checked == true && document.student_detail.result2.checked == true){
alert('Select any one result');
return false ;
}
}
function deleteRow(obj) {
var index = obj.parentNode.parentNode.rowIndex;
var table = document.getElementById("new");
table.deleteRow(index);
}
function myFunction() {
var x = document.getElementById('myTable');
if (x.style.display === 'none') {
x.style.display = 'block';
} else {
x.style.display = 'none';
}
var change = document.getElementById("toggle");
if (change.innerHTML === "Hide Form")
{
change.innerHTML = "Show Form";
}
else {
change.innerHTML = "Hide Form";
}
}
function hideElem(){
document.getElementById('new').style.visibility = "hidden";
}
function showElem(){
document.getElementById('new').style.visibility = "visible";
}.abc table{
width: 100%;
border-collapse: collapse;
}
.abc table th{
border: 1px solid #000;
}
.abc table td{
border: 1px solid #000;
}
h2{
color: black;
text-shadow: 2px 2px 8px #FF0000
}
input[type=text],select,input[type=number]{
width: 100%;
padding: 12px 20px;
margin: 8px 0;
display: inline-block;
border: 2px solid #ccc;
border-radius: 4px;
box-sizing: border-box;
}
input[type=button] {
width: 50%;
background-color: #4CAF50;
color: white;
padding: 14px 10px;
margin: 8px 0;
border: none;
border-radius: 4px;
cursor: pointer;
}
input[type=button]:hover {
background-color: #45a049;
}
div {
border-radius: 5px;
background-color: #f2f2f2;
padding: 20px;
}
<form name="student_detail" method="post" action="#" onsubmit="return addtable();">
<table id="myTable" >
<tr>
<td><h2>School Management Application</h2></td>
</tr>
<tr>
<td><label for="roll_number">Roll no</label></td>
<td><input type="text" id="roll_number" name="roll_number" placeholder="Roll Number"></td>
</tr>
<tr>
<td><label for="student_name">Student name</label></td>
<td><input type="text" id="student_name" name="student_name" placeholder="Student Name"></td>
</tr>
<tr>
<td><label for="class">Class</label></td>
<td><select name="class" id="class">
<option value="1">1</option>
<option value="2">2</option>
<option value="3">3</option>
<option value="4">4</option>
<option value="5">5</option>
<option value="6">6</option>
<option value="7">7</option>
<option value="8">8</option>
<option value="9">9</option>
<option value="10">10</option>
</select></td>
</tr>
<tr>
<td><label>Gender</label></td>
<td><input type="radio" class="gender" name="gender" value="male">Male
<input type="radio" class="gender" name="gender" value="female">Female</td>
</tr>
<tr>
<td><label for="age">Age</label></td>
<td><input type="number" id="age" name="age" placeholder="Age"></td>
</tr>
<tr>
<td><label for="phone_number">Phone number</label></td>
<td><input type="text" id="phone_number" name="phone_number" placeholder="Phone Number"></td>
</tr>
<tr>
<td><label>Result</label></td>
<td><input type="checkbox" class="result" name="result1" value="passed" >Passed
<input type="checkbox" class="result" name="result2" value="failed" />Failed</td>
</tr>
<tr>
<td><input type="button" value="Submit" onclick="addtable()"></td>
</tr>
</table>
</form>
<table>
<tr>
<td><input type="button" value="Hide Form" id="toggle" onclick="myFunction()">
<input type="button" value="Hide table" id="tab" onclick="hideElem()">
<input type="button" value="Show table" id="tab1" onclick="showElem()"></td>
</tr>
</table>
<div class="abc">
<table id="new">
<tr>
<th>Rollno</th>
<th>Student name</th>
<th>Class</th>
<th>Gender</th>
<th>Age</th>
<th>Phone number</th>
<th>Result</th>
</tr>
</table>
</div>
如果再次输入相同的卷号，则需要提醒。之后 提交和显示警告信息
任何人都可以帮我这样做
答案 0 :(得分：0)
这是一个检查重复的函数
checkDupes($("#someId"));
function checkDupes(itemArray) {
var isdupe = false;
for (var i = itemArray.length - 1; i >= 0; i--) {
var value = itemArray[i].value;
if (value == null || value == '' || value.trim().length == 0) {
itemArray[i].style.backgroundColor = 'red';
} else {
if (i > 0) {
for (var j = i - 1; j > -1 && i > 0; j--) {
if (value.trim().toLowerCase() == itemArray[j].value.trim().toLowerCase()) {
itemArray[i].style.backgroundColor = 'red';
isdupe = true;
}
}
if (!isdupe) {
itemArray[i].style.backgroundColor = 'transparent';
}
}
}
}
}