在javascript中获取多个基于td id的值时显示错误

这是我的表,具有不同的值。当通过 javascript 访问基于 td id 的值时,它仅返回单个值。


<!DOCTYPE html>

<html>

<head>

<meta charset="ISO-8859-1">

<title>Insert title here</title>

</head>

<body>

 <table>

  <tr>

      <td class="srno"> 1. </td>


      <td class="check"><input type="checkbox" name="checkbox" value="9"></td>

      <td class="cname">11534420 </td>

      <td class="comName" id="9 ">student1 </td>

      <td scope="col" id="contactno" style="display:none;">123456789</td>

      <td scope="col" id="stuname" style="display:none;">student1</td>

      <td class="attendance"><select name="selattend">

      <option value="present">Present</option>

      <option value="absent">Absent</option>

      </select></td>

      </tr>

   <tr>

      <td class="srno"> 2. </td>


      <td class="check"><input type="checkbox" name="checkbox" value="10"></td>

      <td class="cname">14395673 </td>

      <td class="comName" id="10 ">student2 </td>

      <td scope="col" id="contactno" style="display:none;">123456780</td>

      <td scope="col" id="stuname" style="display:none;">student2</td>

      <td class="attendance"><select name="selattend">

      <option value="present">Present</option>

      <option value="absent">Absent</option>

      </select></td>

      </tr>

     <tr>

      <td class="srno"> 3. </td>


      <td class="check"><input type="checkbox" name="checkbox" value="11"></td>

      <td class="cname">17256926 </td>

      <td class="comName" id="11 ">student3 </td>

      <td scope="col" id="contactno" style="display:none;">123456712</td>

      <td scope="col" id="stuname" style="display:none;">student3</td>

      <td class="attendance"><select name="selattend">

      <option value="present">Present</option>

      <option value="absent">Absent</option>

      </select></td>

      </tr>

      </table>

 </body>

</html>

这是我的外部 javascript 代码是


function getvalue()

{

var contactno=document.getElementById("contactno").innerText;

    alert(contactno);

var stuname=document.getElementById("stuname").innerText;

    alert(stuname);

}

它仅返回第一个 td id 值。如何在javascript中获取所有基于id的td值的数组


慕妹3146593
浏览 38回答 1
1回答

波斯汪

getElementById() 方法将始终仅返回第一个找到的 DOM 元素,而不是列表!对于结果中需要多个元素的此类查询,请使用 querySelectorAll() 方法。例子:var elements = document.querySelectorAll('#contactno');for(i=0; i<elements.length; i++) {&nbsp; &nbsp; console.log(elements[i].innerText)}<!DOCTYPE html><html><head><meta charset="ISO-8859-1"><title>Insert title here</title></head><body>&nbsp;<table>&nbsp; <tr>&nbsp; &nbsp; &nbsp; <td class="srno"> 1. </td>&nbsp; &nbsp; &nbsp; <td class="check"><input type="checkbox" name="checkbox" value="9"></td>&nbsp; &nbsp; &nbsp; <td class="cname">11534420 </td>&nbsp; &nbsp; &nbsp; <td class="comName" id="9 ">student1 </td>&nbsp; &nbsp; &nbsp; <td scope="col" id="contactno" style="display:none;">123456789</td>&nbsp; &nbsp; &nbsp; <td scope="col" id="stuname" style="display:none;">student1</td>&nbsp; &nbsp; &nbsp; <td class="attendance"><select name="selattend">&nbsp; &nbsp; &nbsp; <option value="present">Present</option>&nbsp; &nbsp; &nbsp; <option value="absent">Absent</option>&nbsp; &nbsp; &nbsp; </select></td>&nbsp; &nbsp; &nbsp; </tr>&nbsp; &nbsp;<tr>&nbsp; &nbsp; &nbsp; <td class="srno"> 2. </td>&nbsp; &nbsp; &nbsp; <td class="check"><input type="checkbox" name="checkbox" value="10"></td>&nbsp; &nbsp; &nbsp; <td class="cname">14395673 </td>&nbsp; &nbsp; &nbsp; <td class="comName" id="10 ">student2 </td>&nbsp; &nbsp; &nbsp; <td scope="col" id="contactno" style="display:none;">123456780</td>&nbsp; &nbsp; &nbsp; <td scope="col" id="stuname" style="display:none;">student2</td>&nbsp; &nbsp; &nbsp; <td class="attendance"><select name="selattend">&nbsp; &nbsp; &nbsp; <option value="present">Present</option>&nbsp; &nbsp; &nbsp; <option value="absent">Absent</option>&nbsp; &nbsp; &nbsp; </select></td>&nbsp; &nbsp; &nbsp; </tr>&nbsp; &nbsp; &nbsp;<tr>&nbsp; &nbsp; &nbsp; <td class="srno"> 3. </td>&nbsp; &nbsp; &nbsp; <td class="check"><input type="checkbox" name="checkbox" value="11"></td>&nbsp; &nbsp; &nbsp; <td class="cname">17256926 </td>&nbsp; &nbsp; &nbsp; <td class="comName" id="11 ">student3 </td>&nbsp; &nbsp; &nbsp; <td scope="col" id="contactno" style="display:none;">123456712</td>&nbsp; &nbsp; &nbsp; <td scope="col" id="stuname" style="display:none;">student3</td>&nbsp; &nbsp; &nbsp; <td class="attendance"><select name="selattend">&nbsp; &nbsp; &nbsp; <option value="present">Present</option>&nbsp; &nbsp; &nbsp; <option value="absent">Absent</option>&nbsp; &nbsp; &nbsp; </select></td>&nbsp; &nbsp; &nbsp; </tr>&nbsp; &nbsp; &nbsp; </table>&nbsp;</body></html>
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