src/Datastructure/Stackqueue/Queue.php
public function queueSize(): int {
        if ($this->tail > $this->head) return 0;
        return $this->head - $this->tail;
    }
public function queueSize(): int {
        if ($this->tail > $this->head) return 0;
        return $this->head - $this->tail;
    }
public function queueSize ( ) : int { if ( $ this -> tail > $ this -> head ) return 0 ; return $ this -> head - $ this -> tail ; }
stores the number of items of the queue to the size member of this class and returns it

@return int
@deprecated
stores the number of items of the queue to the size member of this class and returns it