Passing a Variable from One PHP Include File to Another: Global VS. Not

Passing a variable from one php include file to another: global vs. not

The parent file has access to variables in both included files

When including files in PHP, it acts like the code exists within the file they are being included from. Imagine copy and pasting the code from within each of your included files directly into your index.php. That is how PHP works with includes.

So, in your example, since you've set a variable called $name in your front.inc file, and then included both front.inc and end.inc in your index.php, you will be able to echo the variable $name anywhere after the include of front.inc within your index.php. Again, PHP processes your index.php as if the code from the two files you are including are part of the file.

The included file doesn't have access to the other included file

When you place an echo within an included file, to a variable that is not defined within itself, you're not going to get a result because it is treated separately then any other included file.

In other words, to do the behavior you're expecting, you will need to define it as a global.

Passing variables to included file for use in another file

a.php

   $b = "this_from_a";
   include("t1.php");

t1.php

   echo "<a href=t2.php?var=".$b.">link</a>";

t2.php

echo $_GET['var'];

OUTPUT:

this_from_a

WAY2:
Use session.

PHP, getting variable from another php-file

You can, but the variable in your last include will overwrite the variable in your first one:

myfile.php

$var = 'test';

mysecondfile.php

$var = 'tester';

test.php

include 'myfile.php';
echo $var;

include 'mysecondfile.php';
echo $var;

Output:

test

tester

I suggest using different variable names.

Passing variables from one file using include and to another file using href functions

when using an if statement, make sure you predefine the variable so you know if things go wrong

$myDate = 'bad stuff happened'; //Example.
$someVar = true; //Indicates a true value for the if in this example.

if ($someVar) {
    $myDate = new Date('Y-m-d'); //Today.
}

when passing this as $_GET parameters in a link, you can get a hold of these by using the describing word before the '=' sign, e.g. in index.php, if you want to call the date, you would have to call $myDate, however if you are in file 2, and lets say your url looks like this inside the link:

<a href="www.mydomain.com/?todayis=<?=$myDate?>&category=<?=$category?>" />click</a>

on the next page, you can access the date by using $_GET['todayis'] since that is the name of the $_GET variable.

If none of these show up, you know for sure it's not getting passed to your next page.

Passing variables in PHP from one file to another

Include the file you would like the variable to be accessible within, like so

include('somefile.php')

and at the top of that file you might need put something like [depending on server configurations]

global $pubname

But in most cases you would not need to do this.

In regards to security, depending on how $pubname is set, your query may or may not be prone to sql injection.

Note: There are other means to include() files such as include_once(), require() and require_once(), from php.net:

The documentation below also applies
to require(). The two constructs are
identical in every way except how they
handle failure. include() produces a
Warning while require() results in a
Fatal Error. In other words, use
require() if you want a missing file
to halt processing of the page.
include() does not behave this way,
the script will continue regardless.
Be sure to have an appropriate
include_path setting as well. Be
warned that parse error in required
file doesn't cause processing halting
in PHP versions prior to PHP 4.3.5.
Since this version, it does.

Not able to pass variable from different php file

What tim said is correct, one other approach without implementing OOP is using the superglobal $GLOBAL

ex.
$GLOBALS['link']

reference: https://www.php.net/manual/en/reserved.variables.globals.php

Passing Variable FROM Included PHP File To Parent Script

Make sure you global $variable the variable everytime you want to use it in a new function, or even within a new script. This will make sure that the variable is available everywhere that you need it.

---

Related Topics