在php函数中使用外部包含的文件

Question

I'm writing a functions.php file...now, some functions must access the db. I have a db_connect.php file which contains the connection script. I've included it in functions.php with:

require "sys/db_connect.php";

but how to use the connection script ($con) inside

function a() {
   ...
}
function c() {
   ...
}

and so on? I've tried already setting $con variable as global, but no success.

Answer 1

There are three ways to do this, either accessing the value using $GLOBALS, declaring it as a global variable or passing it as a parameter

1st way:

include 'db_connect.php';
    function a() {
        $link = $GLOBALS['con'];
        // you can assign $GLOBALS['con'] or use it as a normal variable
    }

2nd way:

include 'db_connect.php';
function a() {
    global $con;
    // then use it as a normal variable
 }

3rd way:

function a($con) {
    // use the variable
}

Read more about variable scopes here