我有一個(gè)JavaScript數(shù)組，該數(shù)組取自html形式的Checkboxes。我正在使用name =“ DayChosen []”將數(shù)據(jù)放入可以傳遞給Ajax的數(shù)組中。我知道數(shù)據(jù)在登錄到控制臺(tái)時(shí)會(huì)進(jìn)入數(shù)組，但是在PHP頁(yè)面上似乎丟失了。我正在嘗試收集選定的項(xiàng)目并打開(kāi)一個(gè)新頁(yè)面并將數(shù)據(jù)發(fā)布到此頁(yè)面。我嘗試將其編碼為json，然后使用PHP對(duì)其進(jìn)行解碼，但是我一直得到一個(gè)空值。我也嘗試過(guò)使用JSON，但仍然無(wú)法正常工作。我已經(jīng)使用var_dump來(lái)發(fā)現(xiàn)我正在返回一個(gè)空值。   <form>     <input type = "checkbox" class="CourseDay" name = "DayChosen[]"  value = "Legal"><i class="checkbox-pposition DayChosen">Legal Module</i><br>            <input type = "checkbox" class="CourseDay" name = "DayChosen[]"  value = "Day 1"/><i class="checkbox-pposition DayChosen">Day 1</i><br>    <input type = "checkbox" class="CourseDay" name = "DayChosen[]"  value = "Rodent"/><i class="checkbox-pposition DayChosen">Day 2 Rodent</i><br>    <input type = "checkbox" class="CourseDay" name = "DayChosen[]"  value = "Large animal"><i class="checkbox-pposition DayChosen">Day 2 Large animal </i><br>    <input type = "checkbox" class="CourseDay" name = "DayChosen[]"  value = "Aquatic"><i class="checkbox-pposition DayChosen">Day 2 Aquatic</i><br>    <input type = "checkbox" class="CourseDay" name = "DayChosen[]"  value = "Wildlife"><i class="checkbox-pposition DayChosen">Day 2 Wildlife</i><br><select class="Register-Multiple form-control">     <option disabled selected value > -- Select number of Students to Register -- </option>  <?php       for ($x = 1 ; $x <= 10; $x++) {         echo '<option value = '.$x.'>'.$x.'</option>';      }   ?></select>     <input type="submit" id = "Register" class="col-6 text-center btn btn-primary Register" value="Register">  </form>  <script type="text/javascript">  $('.Register-Multiple').on('change', function (e){var courses = [];$("input[type=checkbox]:checked").each ( function() {      courses.push($(this).val());      console.log($(this).val());});$.ajax({       type: "POST",       url:  '../../wp-content/themes/traffica/Multiple- registration.php',       data: {courses:courses}, // serializes the form's elements.       success: function(data)       {          console.log(data);