} echo "Empty stack , nothing to pop"; } public function first() { return $this->stackArray[$this->index]; } public function last() { return $this->stackArray[0]; } public function GetElement($position) { if ($position <= $this->index + 1) { $arrayposition = $this->index + 1 - $position; return $this->stackArray[]; } echo "invalid position", "<br>"; } } $mystack = new stack(); $mystack->push(1); $mystack->push(4); $mystack->push(5); echo $mystack->first(), "<br>"; echo $mystack->last(); //$mystack->pop() //echo $mystack->pop(); echo $mystack->pop(); //$mystack->pop(); echo $mystack->GetElement();