PHP 8 version for a linked-list stack implementation.

stack/php/linked_stack.php

@@ -0,0 +1,57 @@
+<?php
+
+declare(strict_types=1);
+
+class Node {
+    public function __construct(private int $value, private ?Node $next = null){
+
+    }
+    public function push(int $value): Node {
+        return new Node($value, $this);
+    }
+
+    public function print():void{
+        echo $this->value . ' ';
+        $this->next?->print();
+    }
+
+    public function pop():array{
+        return [
+            $this->value,
+            $this->next
+        ];
+    }
+}
+
+$root = new Node(0);
+$root->print();
+echo PHP_EOL;
+$root = $root->push(1);
+$root->print();
+echo PHP_EOL;
+$root = $root->push(2);
+$root->print();
+echo PHP_EOL;
+[$value, $root] = $root->pop();
+echo 'popped value: ' . $value . ' ' . PHP_EOL;
+$root->print();
+echo PHP_EOL;
+[$value, $root] = $root->pop();
+echo 'popped value: ' . $value . ' ' . PHP_EOL;
+$root->print();
+echo PHP_EOL;
+[$value, $root] = $root->pop();
+echo 'popped value: ' . $value . ' ' . PHP_EOL;
+$root?->print();
+
+/**
+ Produced output:
+0
+1 0
+2 1 0
+popped value: 2
+1 0
+popped value: 1
+0
+popped value: 0
+ */