PHP     . PHP       .

 PHP            .

  .

<html>
<head>
<title>Helloy world!/title>
</head>
<body>
<?php

print "Hello world!";

exit;

?>

<body>
</body>

     php "<?php print "Helloy world!"; ?> 
  html       , 
   php       "helloy world!"   html.

     "<?php"   "?>"      
     ,    ,        
         (    html, 
     ).

      ";"      .

   . 
     "$"      , 
      ,       : $q, $w1. 
    $_q, $1q.

     :

<?php

$q="Hello world!";

print $q;

exit;

?>

     "Helloy world!". 
         , 
  ,  -       (  ) 
   ,          , 
   .    php     , 
   ,   ,  string,   ,  integer   .