i want to write a php script to find if a given number is prime or not

Question

I have tried to create a code which is

<html>
<body>
 <form method = "post"> 
  <?php
          Number : <input type = "text" name = "prime">;
          <input type = "submit" value ="Submit">;
          $num = $_REQUEST["prime"];
          $flag = 0;
          for($i = 2; $i <= $num/2; $i++)
          {
   if( $num % $i == 0)
   {
           $flag = 1;
              break;
          }
          }
          if($flag == 0)
   echo "$num is a prime number";
          else
   echo "$num is not a prime number";
  ?>
 </form>
</body>
</html>

Whenever i try to run it, i get the error Parse error: syntax error, unexpected '<', expecting end of file in C:\xampp\htdocs\pc.php on line 5

Any help would be appreciated

Although there are quite a few other problems once you get past the syntax. — Nigel Ren, Apr 01 '18 at 14:03
Everything between `` must be valid PHP code. You have HTML at the start. — Peter, Apr 01 '18 at 14:04

score -1 · Answer 1 · answered Apr 01 '18 at 14:05

Your code is wrong. There is no statement in line 5. Corrected code:

<html>
<body>
<?php
    if($_SERVER['REQUEST_METHOD']=='post'){
        $num = $_POST["prime"];
        $flag = 0;
        for($i = 2; $i <= $num/2; $i++)
        {
            if( $num % $i == 0)
            {
                $flag = 1;
                break;
            }
        }
        if($flag == 0)
            echo $num." is a prime number";
        else
            echo $num." is not a prime number";
    }
?>
    <form method = "post" action="#">
        Number : <input type = "text" name = "prime">
        <input type = "submit" value ="Submit">
    </form>
</body>
</html>

This will check current request method. If is is pot

score -1 · Answer 2 · answered Apr 01 '18 at 14:13

You can follow the below procedure for solving your problem

 <html>
<body>
    <?php
        if(isset($_POST['prime']))
        {
            $num = $_POST["prime"];
            $flag = 0;
            for($i = 2; $i <= $num/2; $i++)
            {
                if( $num % $i == 0)
                {
                    $flag = 1;
                    break;
                }
            }
                if($flag == 0)
                    echo "$num is a prime number";
                else
                    echo "$num is not a prime number";
        }


    ?>
    <form method = "post"> 
        <input type = "text" name="prime">
        <input type = "submit" value ="Submit">

    </form>
</body>
</html>

i want to write a php script to find if a given number is prime or not

2 Answers2