Question

我正在尝试将输入值发送到另一个页面。

    $( this ).attr( "href", '?module=module_progress_report&Subject='+ $('input[name=subject]:checked').val()+ '&Centre_Selected_ID='+ encodeURIComponent($( this ).attr('data-centre')) + '&Class_Selected_Year='+ encodeURIComponent($( this ).attr('data-year')) + '&Class_Selected_All='+ encodeURIComponent($( this ).attr('data-all-centre')) +'&StartDate='+$('#report_date_start').val()+'&EndDate=18/12/2016');

下面，

$('input[name=subject]:checked').val()

这总是返回undefined。该值未被选中。如果我选择其中一个选项作为默认值，则会存储其值。我需要做什么？

修改

这是PHP和HTML：

<form class="small-box-footer" style="text-align:left;padding:10px;"  method="post" name="nameHere">

                              <?php
                              $query = "SELECT * FROM subject";
                            //$query="SELECT * FROM $base_name";
                            $result = mysql_query($query);
                            while ($row39 = mysql_fetch_array($result)) {
                                $Referrer_ID = $row39['Subject_ID'];
                                $Referrer_Name = $row39['Subject_Name'];      
                                ?>

<input type="checkbox" class="subject-selected" name="subject" value="<?=$Referrer_ID?>"> <?=$Referrer_Name?><?=$Referrer_ID?><br />

<?php } ?>

</form>

以下是HTML：

<input type="checkbox" class="subject-selected" name="subject" value="2"> GCSE Maths2<br />

                                                         <!--<a href="#" class="small-box-footer" data-id="<?php=$Referrer_Name?>" data-subject="GCSE English"   data-report-range="month">
                                      <i class="fa fa-arrow-circle-right"></i>
                                    </a>  
                                    -->
                                <input type="checkbox" class="subject-selected" name="subject" value="3"> GCSE English3<br />

                                                         <!--<a href="#" class="small-box-footer" data-id="<?php=$Referrer_Name?>" data-subject="GCSE Science"   data-report-range="month">
                                      <i class="fa fa-arrow-circle-right"></i>
                                    </a>  
                                    -->
                                <input type="checkbox" class="subject-selected" name="subject" value="4"> GCSE Science4<br />

                                                         <!--<a href="#" class="small-box-footer" data-id="<?php=$Referrer_Name?>" data-subject="GCSE Art"   data-report-range="month">
                                      <i class="fa fa-arrow-circle-right"></i>
                                    </a>  
                                    -->
                                <input type="checkbox" class="subject-selected" name="subject" value="5"> GCSE Art5<br />

                                                         <!--<a href="#" class="small-box-footer" data-id="<?php=$Referrer_Name?>" data-subject="GCSE Sociology"   data-report-range="month">
                                      <i class="fa fa-arrow-circle-right"></i>
                                    </a>  
                                    -->
                                <input type="checkbox" class="subject-selected" name="subject" value="6"> GCSE Sociology6<br />

                                                         <!--<a href="#" class="small-box-footer" data-id="<?php=$Referrer_Name?>" data-subject="OCR Nationals ICT"   data-report-range="month">
                                      <i class="fa fa-arrow-circle-right"></i>
                                    </a>  
                                    -->
                                <input type="checkbox" class="subject-selected" name="subject" value="8"> OCR Nationals ICT8<br />

                                                         <!--<a href="#" class="small-box-footer" data-id="<?php=$Referrer_Name?>" data-subject="OCR Nationals Sports"   data-report-range="month">
                                      <i class="fa fa-arrow-circle-right"></i>
                                    </a>  
                                    -->
                                <input type="checkbox" class="subject-selected" name="subject" value="9"> OCR Nationals Sports9<br />

                                                         <!--<a href="#" class="small-box-footer" data-id="<?php=$Referrer_Name?>" data-subject="OCR Nationals Business Studies"   data-report-range="month">
                                      <i class="fa fa-arrow-circle-right"></i>
                                    </a>  
                                    -->
                                <input type="checkbox" class="subject-selected" name="subject" value="10"> OCR Nationals Business Studies10<br />

                                                         <!--<a href="#" class="small-box-footer" data-id="<?php=$Referrer_Name?>" data-subject="Entry Science"   data-report-range="month">
                                      <i class="fa fa-arrow-circle-right"></i>
                                    </a>  
                                    -->
                                <input type="checkbox" class="subject-selected" name="subject" value="11"> Entry Science11<br />

                                                         <!--<a href="#" class="small-box-footer" data-id="<?php=$Referrer_Name?>" data-subject="Functional Skills English"   data-report-range="month">
                                      <i class="fa fa-arrow-circle-right"></i>
                                    </a>  
                                    -->
                                <input type="checkbox" class="subject-selected" name="subject" value="12"> Functional Skills English12<br />

                                                         <!--<a href="#" class="small-box-footer" data-id="<?php=$Referrer_Name?>" data-subject="Functional Skills Maths"   data-report-range="month">
                                      <i class="fa fa-arrow-circle-right"></i>
                                    </a>  
                                    -->
                                <input type="checkbox" class="subject-selected" name="subject" value="13"> Functional Skills Maths13<br />

                                                         <!--<a href="#" class="small-box-footer" data-id="<?php=$Referrer_Name?>" data-subject="ESOL"   data-report-range="month">
                                      <i class="fa fa-arrow-circle-right"></i>
                                    </a>  
                                    -->
                                <input type="checkbox" class="subject-selected" name="subject" value="14"> ESOL14<br />

                                                         <!--<a href="#" class="small-box-footer" data-id="<?php=$Referrer_Name?>" data-subject="Preparation for Working Life"   data-report-range="month">
                                      <i class="fa fa-arrow-circle-right"></i>
                                    </a>  
                                    -->
                                <input type="checkbox" class="subject-selected" name="subject" value="15"> Preparation for Working Life15<br />

Answer 1

尝试在控制台上运行相同的代码$('input[name=subject]:checked').val()并查看它给出的内容。

for :checked＃确保您输入的元素类型为checkbox

您也可以使用：

$('input[name="input_name"]').is('checked'); // will return true/false

Answer 2

您需要将checked替换为selected：

$('input[name=subject]:selected').val()

Answer 3

 Syntax: $( "input[value='name']" )
 try this 
 $('input[name="subject"]:checked').val()

$（'input [name = nameofinput]：checked'）。val（）的值未定义

修改

3 个答案: