Nested PHP blocks in HTML-CodePudding

I have a table with 10 rows and 19 columns in MySQL. I am trying to display the content of table in HTML. I wrote the code below for this purpose.

<?php
.
.
.
$con = mysqli_connect($host,$user,$password,$db);
$i="select * from data where user='".$usr."'";
$result=mysqli_query($con,$i);
$matrix = mysqli_fetch_all($result);
        
            
        $row = $matrix[0];
        
        $cell = $row[1];
        echo $cell;
    }

?>

<html>
        <style>
        table {
          border:2px solid black;
          width: 100%;
          margin-left:0%;
        }
        tr, td {
          border:1px solid black;
          width: 1%;
          font-size: 20px;
          text-align:center;
        }
        </style>

        <table>
            <?php
                $b=0;
                while ($b<10) {
                    echo '
                        <tr>
                             <?php
                                $a=0;
                                while ($a<18) {
                                    echo "
                                        <td>
                                            $row[$a]
                                        </td>
                                    ";
                                    $a  ;
                                }
                             ?>
                        </tr>
                    ';
                    $b  ;
                }
            ?>
        </table>
</html>

The code does not work. I also read a similar question that was answered to replace inner <?p ?> with ". ." . I tried this but did not get the expected result. What is wrong with this code?

CodePudding user response：

You are putting an open php tag inside of an echo. Instead, keep them separate.

<table>
<?php
  $b=0;
  while ($b<10) {
    echo '<tr>';
    $a=0;
    while ($a<18) {
      echo "<td>$row[$a]</td>";
      $a  ;
    }
    echo '</tr>';
  $b  ;
  }?>
</table>

In your code, you have this:

...
echo '
  <tr>
     <?php
         $a=0;
         ...

... which has 3 errors. First, anything inside of single quotes in php will not be evaluated (parsed). So, even something like this: echo 'hello $name'; will spit out the output: hello $name whereas echo "hello $name"; (double quotes) will parse the variable $name and will spit out somethign like: hello Sam.

Second, you are trying to open a new php tag when you're already inside a php tag.

Third, and this is really the deal breaker here, you are trying to start a new block of logic ( a loop) inside of an echoed string. This would not work with either single or double quotes. If you look at my answer, I close out the first echo in order to begin the loop.