How does include work in PHP

Question

I have two files X.php and Y.php as shown below and I am not quite able to figure out what the include statement signifies. In both, these cases the code did not do what I expected it to do. So, I would like to know how it works.

Scenario 1: Variable defined in Y is used in X

X.php

<?php
include 'web/y.php';
echo $test;
?>

Y.php

<?php
$test =  'Hello World';
?>

My Expectation: Variable $test should be accessible in X.php after the include statement

Scenario 2: Value printed in Y is used in X

X.php

<?php
include 'web/y.php';
?>

Y.php

<?php
echo 'Hello World';
?>

My Expectation: Hello World should be printed when X.php is accessed

Answer 1

Scenario 1: Variable defined in Y is used in X

Scenario 2: Value printed in Y is used in X

Both work exactly as you want, i.e. output Hello World.

If they didn't work for you, probably, you gave wrong path to y.php.

The directory structure must be as follows:

x.php
web/y.php

If you have these files in the same directory, then you shouldn't put web/ in front of y.php.