PHP：if（isset（$ _ COOKIE ['name']））无效

Question

I made an input form when the user types in a name. a isset($_COOKIE) checks if the made cookie already exists. if the cookie exists you'll get a message: Welcome back. if not you'll get the message: this is your first time here. but somehow i always get the message welcome back.

Here is my code:

<?php 
 if(!empty($_POST)) 
 {
    header("Location:form_data.php");
    setcookie('name',$_POST['name'], time() + (86400 * 30));
 }
 if(isset($_COOKIE['name']))
 {
   echo "Welcome back ".$_COOKIE['name'];
 }else
 {
    echo "hello ".$_COOKIE['name']; echo " this is your first time here.";
    setcookie('name',$_POST['name'], time() + (86400 * 30));
 }

?>

can someone help me with this problem?

Answer 1

setcookie() must be called before any output is sent to the browser. Otherwise it will cause an header error.

In your code:

Change from:

 echo "hello ".$_POST['name']; echo " this is your first time here.";
 setcookie('name',$_COOKIE['name'], time() + (86400 * 30));

To:

  setcookie('name',$_POST['name'], time() + (86400 * 30));
  echo "hello ".$_POST['name']; echo " this is your first time here.";

So no other code will be executed after header() redirection, you should append exit() to it:

So also change:

header("Location:form_data.php");
setcookie('name',$_POST['name'], time() + (86400 * 30));

To:

setcookie('name',$_POST['name'], time() + (86400 * 30));
header("Location:form_data.php"); exit();