package com.encrox.automaten;

public class Stapel {
    
    Object inhalt;
    Stapel next;
    
    private int zaehlen(){
        if (next == null) return 0;
        else return 1+next.zaehlen();
    }
    
    public Stapel(){    
    }
    
    public boolean istLeer(){
        if (zaehlen()==0) return true;
        else return false;
    }
    
    public void ablegen(Object i){
        Stapel element = new Stapel();
        element.inhalt = i;
        element.next = next;
        next = element;
    }
    
    public Object inhaltGeben(){
        if (next != null) return next.inhalt;
        else return null;
    }
    
    public Object entnehmen(){
        if (next != null){
            Object i = next.inhalt;
            next = next.next;
            return i;
        }
        return null;
    }
    
    public String ausgeben(){
        String s="";
        if (inhalt != null){
            s = s+inhalt.toString()+"\n";
        }
        if (next != null){
            s = s + next.ausgeben();
        }
        return s;
    }
    
}