PHP implementation of a stack.

Stack.class.php

<?php

// http://www.cplusplus.com/reference/stack/stack/

class Stack {
	private $_stack = array();

	public function size() {
		return count($this->_stack);
	}

	public function top() {
		return end($this->_stack);
	}

	public function push($value = NULL) {
		array_push($this->_stack, $value);
	}

	public function pop() {
		return array_pop($this->_stack);
	}

	public function isEmpty() {
		return empty($this->_stack);
	}
}