PHP include file that includes a file strange problem!

Question

I face a strange problem including php files. Let me show you the code:

// constants.php
$MYSQL_HOST_PORT = 'localhost:3306';

// functions.php
include 'constants.php';
function getVar()  {
    echo $MYSQL_HOST_PORT;
}

// doSth.php
include 'functions.php';
echo $MYSQL_HOST_PORT; // The variable is visible and echoed normally as expected!
echo getVar(); // The variable is not echoed! its "".

Any ideas ?

Answer 1

For one, the echo in echo getVar(); won't ever print anything, because getVar doesn't return a value.

Secondly, if you (for some reason) want getVar() itself to work correctly, you need to add a global $MYSQL_HOST_PORT; line, to make it look for $MYSQL_HOST_PORT in the global scope.

Answer 2

Rather than globalising the $MYSQL_HOST_PORT variable, why not simply make it a constant?

// constants.php
define('MYSQL_HOST_PORT', 'localhost:3306');

Provided constants.php is included, you can reference the MYSQL_HOST_PORT constant anywhere.

As indicated in zerocrate's answer , the issue is a scoping one. The enclosed scope of the getVar() function does not include $MYSQL_HOST_PORT .

Answer 3

One thing that I can see wrong is that with the line echo getVar(); you are not getting a return value from the function so you can simply write getVar(); by itself.