Unwrapping can not return an empty element?

Code taken from a Data Structure workbook.

public class PilhaContig {
        private Item [] info;
        private int topo;

        public PilhaContig(int qte){
            this.topo = 0;
            this.info = new Item [qte];
        }
        public Item getInfo(){
            return this.info[this.topo-1];
        }
        public int getTopo(){
            return this.topo;
        }
        public boolean eVazia(){
            return (this.topo == 0);
        }
        public boolean eCheia(){
            return (this.topo == this.info.length);
        }
        public boolean empilhar (Item elem){
            if (this.eCheia()) 
                return false;
            else {
                this.info[this.topo]= elem;
                this.topo++;
                return true;
            }   
        }
        public Item desempilhar(){
            if (this.eVazia())
                return null;
            else{
                this.topo--;
                return this.info[this.topo];
            }
        }   

In the stack class the top variable points to the empty memory space above the last item inserted in the stack. If I unpick the last item with this method (decreasing 1 in the variable top this.topo--; and returning the info vector with the index at the top decreased return this.info[this.topo]; ) I would not end up returning the last item of the stack instead of unstacking this item?