为什么PHP总是重定向到同一页面？

Question

I have written this small php page which should redirect users by the value put in the url. But the script does not seem to work. Anything i have missed?

<?php
if ($choice=="stb")
  $redirect="http://www.webpage1.com/";

    elseif ($choice=="player")
        $redirect="http://www.alternativewebpage.com/"; 

    else
        $redirect="http://www.world-tvpro.com/";

header( 'Location: '.$redirect ) ;
?>

If the page is saved at my server as script.php I would execute it like this: http://mypage.com/script.php?choice=stb .. Expected then is to be redirected to www.webpage1.com, but i get redirected to http://www.world-tvpro.com/ no matter what i write.

Answer 1

You are depending on a feature called register_globals , which is dangerous. Rather than letting query string parameters set globals in your script, use the $_GET superglobal:

if ( isset($_GET['choice']) && $_GET['choice'] === 'stb' ) {

For example.

Answer 2

您需要使用$_GET['choice'] （或isset($_GET['choice']) ? $_GET['choice'] : null ）。

Answer 3

This seems to work for me, sometimes not using { } around your statements can cause issues.

<?php
if ($_GET['choice'] == "stb")
{
    $redirect="http://www.webpage1.com/";
} elseif ($_GET['choice'] == "player") {
    $redirect="http://www.alternativewebpage.com/"; 
} else {
    $redirect="http://www.world-tvpro.com/";
}
header( 'Location: '.$redirect );
?>

Also, $_GET['choice'] is how you get variables from the url query string.

Answer 4

PHP uses a series of super global arrays to pass information from the client to the server. They are as follows:

 $_GET, $_POST, $_COOKIE and $_REQUEST

In your case, since your passing the value in the url as a query parameter you should retrieve choice using $_GET:

$choice = $_GET['choice'];

Note: It can also be retrieved using $_REQUEST as request is a super global array containing all the values of $_GET, $_POST, and $_COOKIE.

You would simply do the same as above just with request:

$choice = $_REQUEST['choice'];

Hope this helps.

Answer 5

If you add: $choice = isset($_GET['choice']) ? $_GET['choice'] : false; $choice = isset($_GET['choice']) ? $_GET['choice'] : false; above the entire IF statement, then the code should be fine.

Also, while the IF statement is fine, a case statement could work nicely as well:

$choice = isset($_GET['choice']) ? $_GET['choice'] : false;
switch($choice){
    case "stb":
        $redirect = 'http://www.webpage1.com/'; break;
    case "player":
        $redirect = 'http://www.alternativewebpage.com/'; break;
    default:
        $redirect = 'http://www.world-tvpro.com/';
}
header("Location: ".$redirect);
exit;