How to get a variable inside a function?

Question

PHP

$a=22;
function test(){
return $a;
}
echo test();

Why doesn't it work? Why is variable a not available inside the function ?

Answer 1

Scope as if
global $a write down

Answer 2

As far as I understand, you wrote before in JavaScript.
https://medium.com/devschacht/glossary-of-modern-j...
pay attention to the concepts of
Cleanliness, Condition
So in PHP, and especially after the appearance of OOP in it , the
use of global is a bad form.
This is the fundamental difference between PHP and JS.
With each request, the script execution starts from scratch, i.e. without special measures,
the script does not know what the user has done before.

Answer 3

I would do so

$a = 22;
$test = function () use ($a) {
return $a;
};
echo $test();