Just started learning PHP...

looking at some code with statement:

$_SESSION[user][id] = $_POST[login_email] ? $_POST[login_email]: $_SESSION[user][id];

need to understand what this statement does
where can I find info on the operators ? :

Thanks , did not find info in my Beginning PHP4 book

http://us4.php.net/manual/en/language.expressions.php

Basically, this is what this line is doing:

if($_POST[login_email])$_SESSION[user][id] = $_POST[login_email];

HTH,

-Snib <><
http://www.snibworks.com
There are only two stupid questions: the one you don't ask, and the one you ask more than once ;)

Thanks
most helpful

That's called the ternary operator, it's an expression. You can find it in the PHP manual here:
http://www.php.net/manual/en/language.expressions.php

What happens is there are three subexpressions within the expression

$first? $second : $third;

The $first evaluates to a simple boolean. If it's true, the second subexpression is evaluated, which is the $second variable in the above example. If the $first subexpression evaluates to false, the third subexpression is evaluated.

Often times this can be represented in an identical if/else chain.

The ternary expression:
$foo = ($_POST['field'])? true : false;

is the same as this if/else chain:
if ($_POST['field'])
{
    $foo = true;
}
else
{
    $foo = false;
}

HTH!

Regards,
Rich

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