Anonymous functions and closure in PHP

basic-global.php

<?php
$count = 0;
function increase_count() {
    global $count;
    $count++;
}
increase_count();
echo $count;

closure-in-javascript.js

var count = 2;
decrease_count = function() {
  count--;
};
decrease_count();
document.write( count );

full-closure-count-2.php

<?php
function create_closure( $count ) {
    return function() use ( &$count ) {
        return $count--;
    };
}
$closure = create_closure( 10 );
$another_closure = create_closure( 20 );

echo $closure(); // 10
echo $another_closure(); // 20
echo $closure(); // 9
echo $closure(); // 8
echo $another_closure(); // 19

full-closure-count.php

<?php
function create_closure( $count ) {
    return function() use ( &$count ) {
        return $count--;
    };
}
$closure = create_closure( 10 );

echo $closure(); // 10
echo $closure(); // 9
echo $closure(); // 8

function-literal-global.php

<?php
$count = 0;
function increase_count() {
    global $count;
    $count++;
}
increase_count();

$increase_count_again = function() {
    global $count;
    $count++;
};
$increase_count_again();

echo $count; // should be 2

global-inner-function.php

<?php
$count = 0;
function increase_count() {
    $count2 = 1;
    function increase_count_again() {
        global $count, $count2;
        $count++;
        $count2++;
    }
    increase_count_again();
    return $count2;
}
echo increase_count();
echo $count;

simple-naive-closure-reference.php

<?php
$count = 1;
$decrease_count = function() use ( &$count ) {
    $count--;
};
$decrease_count();
echo $count;

simple-naive-closure-value.php

<?php
$count = 1;
$decrease_count = function() use ( $count ) {
    $count--;
};
$decrease_count();
echo $count;