这个T_IF错误是什么意思？

Question

<?php
$to = "[e-mail]";
$subject = "Reparasjon av " . $_REQUEST['type'] . " fra mysite.no";
$types = if(!empty($_REQUEST['type'])) {echo($_REQUEST['type'] . ". ");};
$reps = if(!empty($_REQUEST['rep'])) {echo($_REQUEST['rep']);};
$message =  $types . . $reps . "

Kommentarer:
" . $_REQUEST['kommentarer'] . "

Fra:
" . $_REQUEST['navn'] . "
Telefon: " . $_REQUEST['telefon'] . "
Email: " . $_REQUEST['email'] . "
Bosted: " . $_REQUEST['bosted'];
$headers =  "From: " . $_REQUEST['email'] . "
" . 'MIME-Version: 1.0' . "
" . 'Content-type: text/plain; charset=UTF-8' . "
";
if (mail($to, '=?UTF-8?B?'.base64_encode($subject).'?=', $message, $headers)) {
   header( 'Location: http://www.mysite.no/' );
  } else {
   header( 'Location: http://www.mysite.no/' );
  }
?>

It says there's a T_IF error in line 4. What's the problem?

Answer 1

You can't use if there, it's a syntax error. Technically if is a statement, not an expression. That means you can't use it in an assignment like $types = if (...).