Javascript 在循环中从php中的下拉列表中获取值？

我想从下拉列表和值索引中获取值。循环每次以不同的长度运行，例如一次循环运行5次并创建5行。下一次可能是30次，并创建30行。每行有2个下拉列表。请帮助我如何获得每个下拉列表和索引的值。 以下是代码：

    '
    <div>
                <form name="viewdata" method="post" onChange="this.form.submit()">
                    <table>
                        <tr colspan=2>
                    <td><input type="checkbox" name="BSSE" value="BSSE" >BSSE&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp</input></td>
                    <td><input type="checkbox" name="BCS" value="BCS" >&nbsp&nbsp&nbsp&nbsp&nbsp&nbspBCS&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp</input></td>
                    <td><input type="checkbox" name="BSTN" value="BSTN" >&nbsp&nbsp&nbsp&nbsp&nbsp&nbspBSTN&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp</input></td>
                </tr>
                <tr>                       
                    <td><input type="checkbox" name="MTH" value="MTH" >MTH&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp</input></td>
                    <td><input type="checkbox" name="MGT" value="MGT" >&nbsp&nbsp&nbsp&nbsp&nbsp&nbspMGT&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp</input></td>
                    <td><input type="checkbox" name="EEE" value="EEE" >&nbsp&nbsp&nbsp&nbsp&nbsp&nbspEEE&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp</input></td>
                    <td><input type="checkbox" name="CSC" value="CSC" >&nbsp&nbsp&nbsp&nbsp&nbsp&nbspCSC&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp</input></td>
                    <td><input type="checkbox" name="HUM" value="HUM" >&nbsp&nbsp&nbsp&nbsp&nbsp&nbspHUM&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp</input></td>
                </tr>
                <tr>
                    <td>
                <button type="submit" class="btn btn-success btn-sm">View</button>
            </td>
                </tr>
                    </table>
                </form>
            </div>
            <form method = "post">
            <table class="table table-striped table-bordered table-hover" id="dataTables-example">

<?php
$programs_title = array();
$programs_id = array();


$courses_title = array();
$courses_id = array();

$classes = array();
$time_table = array();

$sections_id = array();
$faculty_selected_course = array();

$allocation1 = array();
$allocation2 = array();
$course_loop_array = array();

if(isset($_POST['BSSE'])) {$programs_title[]=$_POST['BSSE'];}
if(isset($_POST['BCS'])) {$programs_title[]=$_POST['BCS'];}
if(isset($_POST['BSTN'])) {$programs_title[]=$_POST['BSTN'];}

if(isset($_POST['MTH'])) {$courses_id[]=$_POST['MTH'];}
if(isset($_POST['MGT'])) {$courses_id[]=$_POST['MGT'];}
if(isset($_POST['EEE'])) {$courses_id[]=$_POST['EEE'];}
if(isset($_POST['CSC'])) {$courses_id[]=$_POST['CSC'];}
if(isset($_POST['HUM'])) {$courses_id[]=$_POST['HUM'];}

$conn = mysql_connect("localhost","root","") or die ("cannot connect");
mysql_select_db('dims') or die("cannot connect to database");

$sql = "SELECT * FROM `user` WHERE email_id='hhh@comsats.edu.pk'";
$result = mysql_query($sql);
while($row1 = mysql_fetch_array($result)){
        $other_faculty[] = $row1['first_name'];
}

foreach ($programs_title as $prog) {

$sql = "SELECT * FROM program WHERE program_title = '$prog'";
$result1 = mysql_query($sql);

if(is_null($result1)){
    echo die(mysql_error());
}

while($row = mysql_fetch_array($result1)){
    $programs_id[] = $row['program_id'];
}

}

foreach ($programs_id as $prog_id) {
$sql = "SELECT * FROM time_table WHERE program_id = '$prog_id'";
$result = mysql_query($sql);

if(is_null($result)){
    echo die(mysql_error());
}

while($row = mysql_fetch_array($result)){
    if(is_array($sections_id)){
       if(!in_array($prog_id."-".$row['section_id'],$sections_id)){
        $sections_id[] = $prog_id."-".$row['section_id'];
    } 
    }
    else{
        $sections_id[] = $prog_id."-".$row['section_id'];
    }


}

}

$section_loop = 1;

foreach ($sections_id as $class) {

    $courses = array();

    $split = preg_split('/-/', $class);

    $program = $split[0];
    $section = $split[1];

    $sql = "SELECT * FROM time_table WHERE program_id = '$program' AND section_id = '$section'";
    $result = mysql_query($sql);

    if(is_null($result)){
    echo die(mysql_error());
    }

    while($row = mysql_fetch_array($result)){
        if(is_array($courses)){
            if(!in_array($row['course_code'], $courses)){
            $courses[] = $row['course_code'];
            }
        }
        else{
            $courses[] = $row['course_code'];
        }

    }

    $sql = "SELECT * FROM program WHERE program_id = '$program'";
    $result = mysql_query($sql);

    if(is_null($result)){
    echo die(mysql_error());
    }

    while($row = mysql_fetch_array($result)){
        $program = $row['program_title'];
    }

    $sql = "SELECT * FROM section WHERE section_id = '$section'";
    $result = mysql_query($sql);

    if(is_null($result)){
    echo die(mysql_error());
    }

    while($row = mysql_fetch_array($result)){
        $section = $row['section_title'];
    }

    if(!in_array($program."-".$section, $classes)){
        $classes[] = $program."-".$section;
    }

    /*foreach ($courses_id as $course) {
        if(!in_array($program."-".$section."-".$course, $time_table)){
        $time_table[] = $program."-".$section."-".$course;
    }
    }*/
    ?>

    <thead>
        <tr class="odd gradeX">
            <th colspan=6><?php echo $program."-".$section."<br>"; ?></th>
        </tr>

        <tr class="odd gradeX">
            <th>#</th>
            <th>Course Code</th>
            <th>Course Title</th>
            <th>Class/Lab</th>
            <th>Faculty</th>
            <th>Other Faculty</th>
        </tr>
    </thead>
<?php
    $course_loop =1;

    foreach ($courses as $course) {
        unset($faculty_selected_course);
            if($course!='JUMMA'){
                foreach ($courses_id as $value) {
                    if(stristr($course, $value)){ ?>
    <tbody>
<?php

                        $sql = "SELECT * FROM course WHERE course_code='$course'";
                        $result2 = mysql_query($sql);

                        if(is_null($result2)){
                            echo die(mysql_error());
                        }

                        while($row2 = mysql_fetch_array($result2)){
                            $course_title = $row2['course_title'];
                            $course_credit_hour = $row2['course_credit_hour'];
                        }

                        $sql = "SELECT * FROM faculty_course_choice WHERE course_choice1='$course' OR course_choice2='$course' OR course_choice3='$course'";
                        $result3 = mysql_query($sql);

                        if(is_null($result3)){
                            echo die(mysql_error());
                        }

                        while($row3 = mysql_fetch_array($result3)){
                            if($course == $row3['course_choice1']){
                                $course_priority = 1;
                                $user = $row3['user_id'];
                            }

                            elseif($course == $row3['course_choice2']){
                                $course_priority = 2;
                                $user = $row3['user_id']."<br>";
                            }

                            elseif($course == $row3['course_choice3']){
                                $course_priority = 3;
                                $user = $row3['user_id']."<br>";
                            }

                            $sql = "SELECT * FROM `user` WHERE user_id='$user'";
                            $result4 = mysql_query($sql);

                            while($row4 = mysql_fetch_array($result4)){
                                $faculty_selected_course[] = $course_priority."::".$row4['first_name'];
                            }
                        }
                        again:
                        ?>
                        <tr class="odd gradeX">
                        <th><?php echo $course_loop++; ?></th>
                        <th><?php echo $course; ?></th>
                        <th><?php echo $course_title; ?></th>
                        <th><?php 
                        if($course_credit_hour==3){
                            echo "Class";
                            $allocation1 [] = $program."-".$section."-".$course."-Class";
                            $allocation2 [] = $program."-".$section."-".$course."-Class";
                        }
                        elseif($course_credit_hour==4){
                            echo "Lab";
                            $allocation1 [] = $program."-".$section."-".$course."-Lab";
                            $allocation2 [] = $program."-".$section."-".$course."-Lab";
                            $course_credit_hour--; ?>
                        </th>

                        <th>
                            <select name= "allocation1[]" class="form-control ">
                                <option>Select Faculty</option>
                                <?php
                                foreach ($faculty_selected_course as $faculty) { ?>
                                <option><?php echo $faculty;  ?></option>
                                <?php
                                }
                                ?>
                            </select> 
                        </th>

                        <th>
                            <select name= "allocation2[]" class="form-control ">
                                <option>Select Other Faculty</option>
                                <?php
                                foreach ($other_faculty as $otherfaculty) { ?>
                                <option><?php echo $otherfaculty;  ?></option>
                                <?php
                                }
                                ?>
                            </select>
                        </th>

                        </tr>
                        <?php goto again;
                        }
                        ?>
                        </th>

                        <th>
                            <select name= "allocation1[]" class="form-control ">
                            <option>Select Faculty</option>
                            <?php
                            foreach ($faculty_selected_course as $faculty) { ?>
                            <option><?php echo $faculty;  ?></option>
                            <?php
                            }
                            ?>
                            </select>
                        </th>

                        <th>
                            <select name= "allocation2[]" class="form-control ">
                                <option>Select Other Faculty</option>
                            <?php
                            foreach ($other_faculty as $otherfaculty) { ?>
                            <option><?php echo $otherfaculty;  ?></option>
                            <?php
                            }
                            ?>
                            </select>
                        </th>

                        </tr>

                        <?php
                    }

                }
            }
    }
    $get_index = $program."-".$section."-".$course_loop;
    $course_loop_array [] = $get_index;
}  
?>

                        <tr>
                            <th colspan="7" >
                                <button type="submit" class="btn btn-success btn-sm">Allocate</button>
                            </th>
                        </tr>
                        </tbody>   

                                </table>
                            </form>
<?php

if(isset($_POST['allocation1'])){
$output = count($_POST['allocation1']);
echo $output;
foreach ($_POST['allocation1'] as $value) {
    if($value == 'Select Other Faculty' OR $value == 'Select Faculty'){

    }
    else{
        echo $value."<br>";
    }

}
}
$allocation1 = $_POST['allocation1'];
foreach ($allocation1 as $value) {
    echo $value."<br>";
}

foreach ($course_loop_array as $lue) {
    echo $lue."<br>";
}

?>


                </div>'

'
BSSE   
       
  nbsp nbsp nbsn nbsp nbsp nbsp nbsp
MTH
        
  nbsp nbsp nbsp nbsp nbsp受试者
  nbsp nbsp nbsp csc nbsp nbsp nbsp
  nbsp nbsp nbsp nbspHUM nbsp nbsp nbsp
看法
不完全确定您要的是什么，但代码应该是这样的：

<th>
    <select name="first_allocation[<?=$rowId?>]">
        <option>Select Faculty</option>
        <? foreach ($faculties as $faculty) { ?>
            <option value="<?=$faculty?>"><?=$faculty?></option>
        <? } ?>
    </select> 
</th>
<th>
    <select name="second_allocation[<?=$rowId?>]">
        <option>Select Other Faculty</option>
        <? foreach ($faculties as $faculty) { ?>
            <option value="<?=$faculty?>"><?=$faculty?></option>
        <? } ?>
    </select>
</th>

其中232和373分别是$rowId的值，在外部循环的每次迭代中都会发生变化

如果您已经拥有所选的学院并希望将其标记为这样，请使用以下命令：

<option value="<?=$faculty?>"<?=($first_allocation[$rowId] === $faculty ? ' selected' : '')?>>
    <?=$faculty?>
</option>

您应该从
名称
属性值中删除美元符号，并为两列使用不同的名称：

<select name="allocation1[]" ...


<select name="allocation2[]" ...

这些数组的索引表示行号减去1（因为它以零开头）。
这可能就是您要找的

主文件，可能是“mainListOfStuff.php”，您可以有如下内容

<form action="processForm.php" method="post">
    <table>
        <tr>
            <th>Main faculty members</th>
            <th>Other factulty members</th>
        </tr>
        <!-- Start of your loop for table rows -->
        <?php
            // YOUR LOOP FOR THE ROWS OF THE TABLE
            // My example loop for this explanation: for (var $i = 0; $i < count([SOME LENGTH OF ROWS]); $i++) {
            // My example start of row: echo "<tr>";
        ?>
                <td>
                    <select name="allocationMain[]" class="form-control mainFaculty">
                        <option selected value="0">Not from this faculty</option>
                        <?php
                            foreach ($faculty_selected_course as $faculty) {
                                echo "<option value=\"". $faculty ."\">". $faculty ."</option>";
                            }
                        ?>
                    </select> 
                </td><td>
                    <select name="allocationOther[]" class="form-control otherFaculty">
                        <option selected value="0">Not from this faculty</option>
                        <?php
                            foreach ($other_faculty as $otherfaculty) {
                                echo "<option value=\"". $otherfaculty ."\">". $otherfaculty ."</option>";
                            }
                        ?>
                    </select>
                </td>
        <!-- End of your loop for table rows -->
        <?php
            // My example end of row: echo "<tr>";
            }
        ?>
    </table>
</form>


主要教员
其他工厂成员
不是从这个学院来的
不是从这个学院来的

当有人交换选择框时，您可以通过放入一些jQuery来清理上面的页面“mainListOfStuff.php”，该jQuery将所选答案交换为“notfromthefaculty”

<script>
    $(function() {
        $("select.otherFaculty").on("change keyup", function(){ // If they choose something in a row in the other faculty
                                                                // Then change the main select to the first "0" value option
            $(this).closest("tr").find("select.mainFaculty").val(0);
        });
        $("select.mainFaculty").on("change keyup", function(){
            $(this).closest("tr").find("select.otherFaculty").val(0);
        });
    });
</script>


$（函数（）{
$（“select.otherFaculty”）。在（“change keyup”上，如果他们在其他faculty的行中选择了某个内容，则使用function（）{//
//然后将主选择更改为第一个“0”值选项
$（this.nexist（“tr”）.find（“select.main”）.val（0）；
});
$（“select.mainfuncil”）。打开（“更改键控”，函数（）{
$（this.nexist（“tr”）.find（“select.otherFaculty”）.val（0）；
});
});

以上代码示例如下>

然后在processForm.php中执行以下操作：

<?php

    if (!isset($_POST["allocationMain"])) exit();   // If no data was submitted then stop the php script here.


    $mainAllocations = $_POST["allocationMain"];    // Both of these arrays should be the same length
    $otherAllocations = $_POST["allocationOther"];  // if the form was submitted properly

    $chosenAllocations = [];

    for( $i = 0; $i < count($mainAllocations); $i++ ) {
        if ( $mainAllocations[$i] == 0 ) {  // If they have not selected "Not from this faculty" for the main select column,
                                            // then select the value in the other select column
            $chosenAllocations[$i] = $otherAllocations[$i];
        } else {
            $chosenAllocations[$i] = $mainAllocations[$i];
        }
    }

    // Use the $chosenAllocations for the rest of your PHP processing

?>


这里面有很多东西让我很困惑。首先，应该只对表的标题使用，而不是对标题下的数据元素使用。为什么这两个select名称是相同的，为什么它们是数组名称（当PHP接收到一个数组类型的POST数据时，名称中带有[]）-这是否意味着有多行select元素？为什么选择名称的样式是PHP变量，前面有$？为什么元素中没有包含值？那么您想要什么-您想要每个select的名称是什么？两个select名称不是一回事。一个选择包含少数教员姓名，而另一个选择包含所有教员姓名。可以从少数教员中进行选择，也可以从所有教员列表中进行选择，但不能同时从两个教员中进行选择。并且有多行。每行有2个选择选项（1是少数教员，2是所有教员）。如果我在中包含值，我会得到什么？如果您包含下面@Marco的答案所示的值，浏览器会将其作为$\u POST变量的值发送，并为所选选项选择“name”。现在我开始明白你的要求了。因此，他们需要能够从一个或另一个选择框中进行选择，但不是同时从两个选择框中进行选择，我明白了。现在就写下我认为是解决您问题的答案，很快就会发布：）这将在循环中起作用？我如何知道“第一次分配”属于哪一行？请参阅我的编辑，刚刚正确理解了您的问题。还是我？
<script>
    $(function() {
        $("select.otherFaculty").on("change keyup", function(){ // If they choose something in a row in the other faculty
                                                                // Then change the main select to the first "0" value option
            $(this).closest("tr").find("select.mainFaculty").val(0);
        });
        $("select.mainFaculty").on("change keyup", function(){
            $(this).closest("tr").find("select.otherFaculty").val(0);
        });
    });
</script>

<?php

    if (!isset($_POST["allocationMain"])) exit();   // If no data was submitted then stop the php script here.


    $mainAllocations = $_POST["allocationMain"];    // Both of these arrays should be the same length
    $otherAllocations = $_POST["allocationOther"];  // if the form was submitted properly

    $chosenAllocations = [];

    for( $i = 0; $i < count($mainAllocations); $i++ ) {
        if ( $mainAllocations[$i] == 0 ) {  // If they have not selected "Not from this faculty" for the main select column,
                                            // then select the value in the other select column
            $chosenAllocations[$i] = $otherAllocations[$i];
        } else {
            $chosenAllocations[$i] = $mainAllocations[$i];
        }
    }

    // Use the $chosenAllocations for the rest of your PHP processing

?>