提交html表单后如何垂直显示输出？

Question

The who;e sequence(having operands , opertors and answer) in output is generating randomly which is perfect. but I want to show that in vertical manner and this is the output I want to show after clicking on generate then Q(2)will show up in the same way but after Q(1).

this is my html form.

    <form action="" method="POST">
              <div class="row">
                 <div class="col-25">
                   <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">How many numbers You want in a sequence:</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"><br>
         <br />

 </form>
   </div>
      <!---Toggle button to select all operations if user select checkbox named "All" -->
           <script language="JavaScript">
                $( '.col-75 .toggle-button' ).click( function () {
                $( '.col-75 input[type="checkbox"]' ).prop('checked', this.checked)
      })
          </script>

Basically I generating a random sequence of arithmetic expressions which is working perfectly without any error. But after clicking generate button the output is showing horizontally and I want to generate it vertically. So how can I do that?

Below is my php code which is generating the sequence perfectly without any error. How can I generate the output vertically?

<?php
  error_reporting(E_ALL & ~E_NOTICE);

  if(isset($_POST['submit']))
  {
       //validation for no of operation selected
       $operation = $_POST['operation'];
       if(empty($operation)) 
             {
               echo "Please Select at least one operation <br/>";
             }
              else
              {  
                 $N = count($operation); //count selected operation
                    echo  "<br />";
                     echo "You have selected $N operation(s):"; 

                            for($i=0; $i < $N; $i++)  //for loop for for operator array.
                               {
                                  echo($operation[$i] . ", "); //display selected operation
                               }
                               echo "<br />";
                     //checkbox operations
                    if($N==1)   //if only one operation is selected
                        {
                             if($operation[0]=='Addition')
                                 {
                                      $rOperators = array('+');                           
                                 }
                                else if($operation[0]=='Subtraction')
                                   {
                                      $rOperators = array('-');
                                    }
                                    else if($operation[0]=='Multiplication')
                                      {
                                      $rOperators = array('*');
                                       }
                                        else
                                          {
                                            $rOperators = array('/');
                                          }
                        }
                    else if ($N==2) //if only two operations are selected by the user
                     {
                        if($operation[0]=='Addition')
                            {
                                if($operation[1]=='Subtraction')
                                    {
                                        $rOperators = array('+','-');
                                    }
                                     else if($operation[1]=='Multiplication')
                                         {
                                           $rOperators = array('+','*');
                                         }
                                          else
                                             {
                                               $rOperators = array('+','/');
                                             }                           
                            }
                            else if($operation[0]=='Subtraction')
                            {
                                if($operation[1]=='Multiplication')
                                     {
                                        $rOperators = array('-','*');
                                     }
                                    else
                                      {
                                        $rOperators = array('-','/');
                                      }
                            }
                              else
                                {
                                  $rOperators = array('*','/');
                                }
                      }
                        else if ($N==3) //if 3 operators gets selected by user
                            {
                                if($operation[0]=='Addition')
                                 {
                                     if($operation[1]=='Subtraction')
                                         {
                                             if($operation[2]=='Multiplication')
                                             {
                                                 $rOperators = array('+','-','*');    
                                             }
                                             else
                                             {
                                                 $rOperators = array('+','-','/');
                                             }

                                         }
                                      else
                                         {
                                              $rOperators = array('+','*','/');
                                         }                         
                                 }
                                 else
                                 {
                                     $rOperators = array('-','*','/');
                                 }
                            }
                        else
                            {
                                $rOperators = array('+','-','*','/');
                            }

             }

//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
                                    $exp = '';     //Generating the expression
                                      foreach($randomOperands as $key=>$value1)
                                         {
                                          $exp .=  $value1 . " " ;  
                                             if(isset($randomOperators[$key]))
                                                {
                                                 $exp .=  $randomOperators[$key] ." "; 
                                                }
                                         }
                                         $res = eval("return ($exp);");//evaluate the expression 
                                           //print expression
                                        echo ("This is Q(".$x."):"), $exp."=". $res."<br>";
                          }
        }
    }
    ?>

Answer 1

Modify the code in which you are generating the expression which you are using as the input to the eval() function. Create another string say $output_string which can be used to output your answer. In this newly created string use proper HTML tags along with the generated string, for formatting it the way you want your output to look like.

It should look something like this:

$exp = '';     //Generating the expression
$output_string = ''; // new string which can be used for generating the output string
foreach ( $randomOperands as $key => $value1 ) {
    $exp .=  $value1 . " " ;
    $output_string .=  $value1 . " <br>" ;
    if ( isset($randomOperators[$key]) ) {
        $exp .=  $randomOperators[$key] ." ";
        $output_string .=  $randomOperators[$key] ." <br> "; 
    }
}
$res = eval("return ($exp);");//evaluate the expression 
//print expression
echo ("This is Q(".$x."): <br>"), $output_string."= <br>". $res."<br>";