how can I include some custom variable from functions.php?

Question

For example, if I add this code to functions.php:

$mysite_address_url="http://my-site.com";

And then add this to one of my .php template files(like index.php or header.php):

<?php echo($mysite_address_url); ?>

It won't work. Why is this happens and how can I achieve this with wordpress please?

Answer 1

WordPress theme files are called thru functions/classes, so variables declared in functions.php are not recognized by other theme files, until you specify you want to use the global value of the variable. Do so like this in your theme template files:

global $mysite_address_url;

you can then use $mysite_address_url as you'd like.

To read more about PHP's variable scope, see this

Also, if you want to use your website's URL, it'd be better to use the home_url() function

Answer 2

I recommend you to store it in WordPress options table using function

add_option() 

function as this is site specific data and not post/category specific.