aktuelle.kurse/old_m411/docs/Daten-Uebungen-CodeBeispiele/MyStack.java
Müller Harald 507e5da390 muh
2022-05-13 11:53:50 +02:00

113 lines
1.5 KiB
Java

public class MyStack {
private Node first;
private int elements;
public MyStack(){
//first = new Node(null); //don't add empty element!
elements = 0;
}
/**
* Adds element to the list (head of list)
* @param element
*/
public void push(Object element){
//the new element is the last in the list:
Node old = first;
first = new Node(element);
first.setNext(old);
elements++;
}
/**
* Removes element from head of list
* @return
*/
public Object pop(){
Object element = first.getItem();
first = first.next;
elements--;
return element;
}
public void showElements(){
Node current = first;
while (current != null){
System.out.println("Elements = " + current.getItem().toString());
current = current.getNext();
}
}
//Inner class with the data structure of the linked list
private class Node{
//these are private
Object item;
Node next;
//constructor
public Node (Object value){
next = null;
item = value;
}
//standard getter and setter methods
public Object getItem() {
return item;
}
public void setItem(Object item) {
this.item = item;
}
public Node getNext() {
return next;
}
public void setNext(Node next) {
this.next = next;
}
}
//TESTS:
public static void main(String[] args) {
MyStack stack = new MyStack();
stack.push("to");
stack.push("be");
stack.push("or");
stack.showElements();
System.out.println("pop....");
stack.pop();
stack.showElements();
}
}