implement stack using linked list in php

Php program for implement stack using linked list. Here problem description and other solutions.

<?php
// Php program for
// Implementation stack using linked list

// Stack Node
class StackNode
{
	public $data;
	public $next;
	public	function __construct($data, $top)
	{
		$this->data = $data;
		$this->next = $top;
	}
}
class MyStack
{
	public $top;
	public $count;
	public	function __construct()
	{
		$this->top = NULL;
		$this->count = 0;
	}
	// Returns the number of element in stack
	public	function size()
	{
		return $this->count;
	}
	public	function isEmpty()
	{
		if ($this->size() > 0)
		{
			return false;
		}
		else
		{
			return true;
		}
	}
	// Add a new element in stack
	public	function push($data)
	{
		// Make a new stack node
		// And set as top
		$this->top = new StackNode($data, $this->top);
		// Increase node value
		$this->count++;
	}
	// Add a top element in stack
	public	function pop()
	{
		$temp = 0;
		if ($this->isEmpty() == false)
		{
			// Get remove top value
			$temp = $this->top->data;
			$this->top = $this->top->next;
			// Reduce size
			$this->count--;
		}
		return $temp;
	}
	// Used to get top element of stack
	public	function peek()
	{
		if (!$this->isEmpty())
		{
			return $this->top->data;
		}
		else
		{
			return 0;
		}
	}
}
class Test
{
	public static
	function main($args)
	{
		// Create new stack 
		$s = new MyStack();
		echo "\n Is empty : ",($s->isEmpty() == 1 ? "true" : "false"), "\n";
		// Add element
		$s->push(15);
		$s->push(14);
		$s->push(31);
		$s->push(21);
		$s->push(10);
		echo "\n Top  : ",$s->peek(), "\n";
		echo " Size : ",$s->size(), "\n";
		echo "\n Is empty : ",($s->isEmpty() == 1 ? "true" : "false"), "\n";
		// Delete Stack Element
		$data = $s->pop();
		echo "\n Pop element ",($data), "\n";
		echo " Size : ",($s->size()), "\n";
		$data = $s->pop();
		echo "\n Pop element ",($data), "\n";
		echo " Size : ",($s->size()), "\n";
	}
}
Test::main(array());

Output

 Is empty : true

 Top  : 10
 Size : 5

 Is empty : false

 Pop element 10
 Size : 4

 Pop element 21
 Size : 3