Data structure essay-php implementation stack

Stack satisfies the principle of last in, first out (LIFO);

The following uses PHP to implement the relevant operation of the stack;

Basic operation of this instance stack:

On-Stack (push): pushes an element into the stack, with the top pointer pointing to the top element of the stack

Stack (POP): Remove elements from the top of the stack, and the top pointer moves to the bottom of the stack;

Empty (IsEmpty): Empty stack when the stack top pointer reverts to the initial pointer state;

Full (Isfull): When the top of the stack equals capacity minus a stack full;

Using a PHP array to implement a simple Operation Stack;

<?PHP/** * Created by Phpstorm. * User:gordon * DATE:2017/8/6 * time:12:58*//** * Class stack simple stack*/classstack{/** * Stack initial pointer*/    ConstTop_init =-1; /** * Stack bottom pointer*/    ConstBOTTOM = 0; /** * @var array stack*/    Private $_stack; /** * @var int stack top pointer*/    Private $_stacktop; /** * @var the capacity of the int stack*/    Private $_stacksize; /** Stack constructor. Initialize stack * @param the size of the int $size stack;*/     Public function__construct ($size)    {        $this->_stack = []; $this->_stacksize =$size; /** * Stack top initial state on the bottom of the stack*/        $this->_stacktop = self::Top_init; }    /** * @method destroy Stack (not required)*/     Public function__destruct () {unset($this-_stack); }    /** * @method into the stack * @param mixed $elem into the stack element * @return bool*/     Public functionPush$elem)    {        if($this-Isfull ()) {            return false; }        $this->_stack[++$this->_stacktop] =$elem; return true; }    /** * @method out stack * @return Mixed|null returns the element at the top of the stack or returns NULL when the stack is empty*/     Public functionpop () {if($this-IsEmpty ()) {            return NULL; }        $result=$this->_stack[$this-_stacktop]; unset($this->_stack[$this-_stacktop]); $this->_stacktop--; return $result; }    /** * @method determine if the stack is empty; * @return BOOL*/     Public functionIsEmpty () {return $this->_stacktop = = = Self::Top_init; }    /** * @method determine if the stack is up to the maximum; * @return bool*/     Public functionIsfull () {return $this->_stacksize-1 = = =$this-_stacktop; }    /** * @method empty stack*/     Public functionClearstack () {$this->_stack = []; $this->_stacktop = self::Top_init; }    /** * @method traversal stack (for testing purposes);*/     Public functionOutputstack () {Echo' Take the traversal stack from bottom to top '.Php_eol;  for($i= Self::bottom;$i<$this->_stacktop + 1;$i++) {            Echo $this->_stack[$i].Php_eol; }        Echo Php_eol; Echo Php_eol; Echo' Take the traversal stack from top to bottom '.Php_eol;  for($i=$this->_stacktop;$i>= Self::bottom;$i--) {            Echo $this->_stack[$i].Php_eol; }    }}

Test the Stack Operation class

$s=NewStack (4);$s->push (1);$s->push (2);$s->push (3);$s->push (4);$s->push (5);$s->outputstack ();//stack from top to Bottom:4 3 2 1$s->pop ();//output:4 stack:3 2 1$s->pop ();//output:3 stack:2 1$s->outputstack ();//Stack:2 1$s->push (5);$s->outputstack ();//stack:5 2 1$s-Clearstack ();Var_dump($s->pop ());//null;

After the test code is very reasonable;

If there is no, please advise

Data structure essay-php implementation stack