点击下一步按钮后如何切换到下一个问题？

Question

我有两个问题 1）如何在单击显示答案按钮时显示答案 2）如何在单击下一步按钮时从一个问题切换到另一个问题 这是我得到的输出的屏幕截图

这是我创建的html格式，

<label for="qnum">Select no.of questions:</label>
                    </div>
                     <div class = "col-75"><input type="number" id="qnum" name="que" value="1"  min="1" max="100"></div>
                     <br /><br />
               </div>
             <br />

        <div class="row">
              <div class="col-25">
                <label for="int">Select no. of Integers:</label></div>
                    <div class="col-75">
                       <select name="select" id="int">
                        <option value="2"> 2 </option>
                        <option value="3"> 3 </option>
                        <option value="4"> 4 </option>
                        <option value="5"> 5 </option>
                        <option value="6"> 6 </option>
                        <option value="7"> 7 </option>
                        <option value="8"> 8 </option>
                        <option value="9"> 9 </option>
                        <option value="10"> 10 </option>
                      </select>
                    </div>
      </div>
      <br /> 

       <div class="row">
           <div class="col-25">
             <label for="dig">Select no. of digits:</label></div>
                <div class="col-75">
                  <select name="digits" id="dig">
                   <option value="1"> 1 digit</option>
                   </select>
              </div>
              <br /><br /><br /><br />
        </div>

          <div class="row">
          <div class="col-25"><label>Select operations:</label><br /></div>
              <div class="col-75">
                <input type="checkbox" id="mix" value="all" class="toggle-button"><label>All</label>
                <input type="checkbox" id="add" name="operation[]" value="Addition" checked><label>Addition</label>
                <input type="checkbox" id="sub" name="operation[]" value="Subtraction"><label>Subtraction</label>
                <input type="checkbox" id="mult" name="operation[]" value="Multiplication"><label>Multiplication</label>
                <input type="checkbox" id="div" name="operation[]" value="Division"><label>Division</label>
               </div>
                <br /><br />
                <br /><br />
            </div><br />


        <input type="submit" name="submit" value="Generate" id = "gen"><br>
        <input type="submit" name="play" value="Play" id="play">
        <br /><br><br><br>

      </form>
   </div>

     <script>
      $( '.col-75 .toggle-button' ).click( function () {
          $( '.col-75 input[type="checkbox"]' ).prop('checked', this.checked)
      })
        </script>

在这里，表达式是随机生成的，这对我来说非常合适。 这是我的php代码，也很好用 但是在屏幕截图中，仅给出了2个问题的输入，这就是为什么它显示2个问题，但是在我的情况下，可能有很多问题取决于用户提供的输入（问题的最大限制为100）。 我该如何解决我刚才提到的那两个问题？

//display sequence having only single digit numbers
if($_POST['digits'] == 1)
     {
        $q = $_POST['que'];
             $previousInt = null;        //Track the previous operand
             $s = $_POST['select'];

                     for ($x = 1; $x<=$q; $x++) //for loop for no. of questions
                        {
                           $randomOperands = array();
                            $randomOperators = array();

                                    // loop over $i n times
                                   for ($i = 1; $i <=$s; $i++) //for loop for no. of integers user entered
                                     {
                                        $nextInt = rand(1, 9); // assign random operand to array slot
                                         $randomOperands[] = $nextInt;
                                            if($i < $s)
                                             {   
                                               if($previousInt === 0) //No operator after last opearnd
                                                  {
                                                 //avoid division-by-zero
                                                   $randomOperators[] = $rOperators[rand(0, 2)];
                                                  }
                                                else
                                                  {
                                                   $randomOperators[] = $rOperators[rand(0, $N-1)];
                                                  } 
                                              }  
                                        $previousInt = $nextInt;
                                      }
                                    // print array values
                                      $exp = '';  
                                      $output_string = " ";
                                          //Generating the expression
                                           foreach($randomOperands as $key=>$value1)
                                         {
                                          $exp .=  $value1 . "" ;
                                             $output_string .= $value1. "<br>";
                                             if(isset($randomOperators[$key]))
                                                {
                                                 $exp .=  $randomOperators[$key]  ."";
                                                  $output_string .= $randomOperators[$key]."<br>";
                                                }

                                         }
                                          //print expression
                                          $res = eval("return ($exp);");//evaluate the expression


                                     ?><center> <?php echo ("This is Q(".$x."): <br>"), $output_string. "<br>________<br>";
                                     ?><br>
                                      <input type="button" name="show" value="Show Answer"><?php echo $res."<br>"; ?><br>
                                     <input type="button" name="next" value="Next" id="butn"><br><br>
                                     </center>

                        <?php

                      }

        }
  }
  ?>

请帮助我。我该如何解决？