PHP variable in header function

Question

I am attempting to pass variables through the URL using the header function as a way to redirect the page. But when the page is redirected it passes the actual variable names rather than the values associated with the variables. I am new to PHP and do not fully understand the syntax so any further explanation as to the proper way to do this would be much appreciated.

header('location: index.php?id=".$_POST[ac_id]."&err=".$login."');

Solution 1

You want:

header("Location: index.php?id=".$_POST['ac_id']."&err=".$login);

You were combining ' and " in this string, which is why it couldn't interpolate the variables properly. In my example above, you are strictly opening the string with " and concatenating the variables with the string.

Solution 2

You have quotes within quotes. Try this instead:

header('location: index.php?id=' . urlencode($_POST['ac_id']) . '&err=' . urlencode($login));

The urlencode() function takes care of any reserved characters in the url.

What I would do instead is use http_build_query(), if you think you will have more than one or two variables in the URL.

header('Location: index.php?' . http_build_query(array(
    'id' => $_POST['ac_id'],
    'err' => $login
)));

Also, you technically can't use relative paths in the location header. While it does work with most browsers, it is not valid according to the RFCs. You should include the full URL.

Solution 3

Try SESSION storage. header is use to redirect the page. and if you really want to pass values through header only then u have genrate url. header('location:destination.php? value1=1&value2=3'); but it is not a good practice for vars. just store values in SESSION global var. B4 the header() redirection call. @the recieve page u have to test, if the session val isset() n !empty() then ... or else ...

Hope this wil help.

Comments

[zerkms]

Both lost quotes in $_POST ;-)

[zerkms]

Both lost quotes in $_POST ;-)

[Stephen]

this will raise a notice because of the unquoted string for the array key.

[zerkms]

Here too... No quotes for $_POST key name

[Stephen]

there is no reason to concatenate the strings & variables, as PHP will expand variables inside double quoted strings

[Mike Lewis]

It is personal preference, and if you want to be nit picking about micro-performance see here(concatenation is slightly faster): stackoverflow.com/questions/13620/…

[Stephen]

It's generally accepted by most developers I've worked with that if you want to do string concatenation, use single quotes, if you want to use inline variable expansion, use double quotes.