PHP会话变量 - 更改页面加载

Question

I'm trying to get a session variable to alternate between 0 and 1 on each page load.

So first time page loads

$_SESSION['turn'] = 0;

Second time

$_SESSION['turn'] = 1;

Third time

`$_SESSION['turn'] = 0;`

and so on.

Then I can call that variable later in the page.

I can't work out how to do this. I've tried a simple IF function but can't get it to work.

Answer 1

Try this where the page is loaded.

$_SESSION['turn']=1-$_SESSION['turn'];

code:

<?php
session_start();
echo $_SESSION['turn'];
$_SESSION['turn']=1-$_SESSION['turn'];
?>

Edit : RiggsFolly !isset() is correct. mine misses it and it will give errors in log. and the first value is not 0