我有四个表，每个表中都有多个单选按钮，现在如何使用javaScript获取所选单选按钮

目前，我正在使用alert检查选择了哪个按钮，但这不起作用。有人能帮我找出错误的地方吗。点击按钮，我想从所有表格中获得所有选中的按钮。在这里，我试图将反馈页面放入我的应用程序中，每个问题将有五个选项，每个选项都有单选按钮

使用

document.querySelector（）

您可以使用集合单选按钮的名称作为表单的命名属性，然后在集合上循环查找已选中的集合，例如


功能已选定（收音机）{
对于（var i=0，iLen=radios.length；ii如果单选按钮位于表单中，则可以使用它们的名称作为表单的命名属性来获取它们的集合。在本例中，
var radios=form.radio
其中表单是对表单DOM元素的引用。循环该集合以获取选中的那个，然后获取其值。您不能使用getElementById具有名称属性或属性，您不能使用它来获取多个元素。如果未选择单选按钮，会返回什么？@RobG one从提供的代码片段中选择一个单选按钮。始终选中一个单选按钮。直到有人“维护”代码并忘记默认选择一个，或者脚本取消选择所有单选按钮，或者……；-）
<div id="tab_2_contents" class="tab_contents">
<div class="table-responsive">
<font style="font-size:large">
<table class="table table-responsive table-striped">
<thead>
1.The instructor set out the course objectives at the begining
</thead>
<tbody>
<tr>
<td>
<label class="label label-success">
<input type="radio" id="radio" value="Poor" name="radio" style="width:20px" checked/>
<span class="lbl padding-8">Poor</span>
</label>
</td>
<td>
<label class="label label-success">
<input type="radio" id="radio" value="Fair" name="radio" style="width:20px" />
<span class="lbl padding-8">Fair</span>
</label>
</td>
<td>
<label class="label label-success">
<input type="radio" id="radio" value="Average" name="radio" style="width:20px" />
<span class="lbl padding-8">Average</span>
</label>
</td>
<td>
<label class="label label-success">
<input type="radio" id="radio" value="Good" name="radio" style="width:20px" />
<span class="lbl padding-8">Good</span>
</label>
</td>
<td>
<label class="label label-success">
<input type="radio" id="radio" value="VeryGood" name="radio" style="width:20px" />
<span class="lbl padding-8">VeryGood</span>
</label>
</td>
<td>
<label class="label label-success">
<input type="radio" id="radio" value="Excellent" name="radio" style="width:20px" />
<span class="lbl padding-8">Excellent</span>
</label>
</td>
</tr>
</tbody>
</table>
<table class="table table-responsive table-striped">
<thead>
2.The instructor communicated his/her ideas clearly
</thead>
<tbody>
<tr>
<td>
<label class="label label-success">
<input type="radio" id="radio1" value="Poor" name="radio" style="width:20px" />
<span class="lbl padding-8">Poor</span>
</label>
</td>
<td>
<label class="label label-success">
<input type="radio" id="radio1" value="Fair" name="radio" style="width:20px" />
<span class="lbl padding-8">Fair</span>
</label>
</td>
<td>
 <label class="label label-success">
<input type="radio" id="radio1" value="Average" name="radio" style="width:20px" />
<span class="lbl padding-8">Average</span>
</label>
</td>
<td>
<label class="label label-success">
<input type="radio" id="radio1" value="Good" name="radio" style="width:20px" />
<span class="lbl padding-8">Good</span>
</label>
</td>
<td>
<label class="label label-success">
<input type="radio" id="radio1" value="VeryGood" name="radio" style="width:20px" />
<span class="lbl padding-8">VeryGood</span>
</label>
</td>
<td>
<label class="label label-success">
<input type="radio" id="radio1" value="Excellent" name="radio" style="width:20px" />
<span class="lbl padding-8">Excellent</span>
</label>
</td>
</tr>
</tbody>
</table>
<table class="table table-responsive table-striped">
<thead>
3.He/She encourages discussion during the lecture
</thead>
<tbody>
<tr>
<td>
<label class="label label-success">
<input type="radio" id="radio2" value="Poor" name="radio" style="width:20px" />
<span class="lbl padding-8">Poor</span>
</label>
</td>
<td>
<label class="label label-success">
<input type="radio" id="radio2" value="Fair" name="radio" style="width:20px" />
<span class="lbl padding-8">Fair</span>
</label>
</td>
<td>
<label class="label label-success">
<input type="radio" id="radio2" value="Average" name="radio" style="width:20px" />
<span class="lbl padding-8">Average</span>
</label>
</td>
<td>
<label class="label label-success">
<input type="radio" id="radio2" value="Good" name="radio" style="width:20px" />
<span class="lbl padding-8">Good</span>
</label>
</td>
<td>
<label class="label label-success">
<input type="radio" id="radio2" value="VeryGood" name="radio" style="width:20px" />
<span class="lbl padding-8">VeryGood</span>
</label>
</td>
<td>
<label class="label label-success">
<input type="radio" id="radio2" value="Excellent" name="radio" style="width:20px" />
<span class="lbl padding-8">Excellent</span>
</label>
</td>
</tr>
</tbody>
</table>
<table class="table table-responsive table-striped">
<thead>
4.He/She competently answered participant's questions
</thead>
<tbody>
<tr>
<td>
<label class="label label-success">
<input type="radio" id="radio3" value="Poor" name="radio" style="width:20px" />
<span class="lbl padding-8">Poor</span>
</label>
</td>
<td>
<label class="label label-success">
<input type="radio" id="radio3" value="Fair" name="radio" style="width:20px" />
<span class="lbl padding-8">Fair</span>
</label>
</td>
<td>
<label class="label label-success">
<input type="radio" id="radio3" value="Average" name="radio" style="width:20px" />
<span class="lbl padding-8">Average</span>
</label>
</td>
<td>
<label class="label label-success">
<input type="radio" id="radio3" value="Good" name="radio" style="width:20px" />
<span class="lbl padding-8">Good</span>
</label>
</td>
<td>
<label class="label label-success">
<input type="radio" id="radio3" value="VeryGood" name="radio" style="width:20px" />
<span class="lbl padding-8">VeryGood</span>
</label>
</td>
<td>
<label class="label label-success">
<input type="radio" id="radio3" value="Excellent" name="radio" style="width:20px" />
<span class="lbl padding-8">Excellent</span>
</label>
</td>
</tr>
</tbody>
</table>
<table class="table table-responsive table-striped">

<thead class="header">
5.Overall rating of the instructor

</thead>

<tbody>
<tr>
<td>
<label class="label label-success">
<input type="radio" id="radio4" value="Poor" name="radio" style="width:20px" />
<span class="lbl padding-8">Poor</span>
</label>
</td>
<td>
<label class="label label-success">
<input type="radio" id="radio4" value="Fair" name="radio" style="width:20px" />
<span class="lbl padding-8">Fair</span>
</label>
</td>
<td>
<label class="label label-success">
<input type="radio" id="radio4" value="Average" name="radio" style="width:20px" />
<span class="lbl padding-8">Average</span>
</label>
</td>
<td>
<label class="label label-success">
<input type="radio" id="radio4" value="Good" name="radio" style="width:20px" />
<span class="lbl padding-8">Good</span>
</label>
</td>
<td>
<label class="label label-success">
<input type="radio" id="radio4" value="VeryGood" name="radio" style="width:20px" />
<span class="lbl padding-8">VeryGood</span>
</label>
</td>
<td>
<label class="label label-success">
<input type="radio" id="radio4" value="Excellent" name="radio" style="width:20px" />
<span class="lbl padding-8">Excellent</span>
</label>
</td>
</tr>
</tbody>
</table>
<table class="table table-responsive table-striped">
<tbody>
<tr>
<td>
<input type="button" class="btn btn-primary" onclick="javaScript:feedback()" id="feedback" value="Submit"/>
</td>
</tr>
</tbody>
</table>
</font>
</div>

</div>

function feedback(){
var s = document.getElementById('radio').value;
alert(s);
}

function feedback(){
var x =document.querySelector('input[name="radio"]:checked').value;
alert(x)
}

function feedback(){
var check = document.querySelector('input:radio[name="radio"]:checked').value;
alert(check);
}