Inheritance...

[MP Olsen]

I'm working on a program using inheritance, and I'm runnning into one problem. In my "Stuff" class, my pop method needs to decrement by one each time subtracting the last word and returning it to be printed. The array from the test will be "code test is this". The result I want from pop is for it to print in seperate lines "this is test code". I tried working with a for loop in the pop method, but didn't have any luck. Maybe I'm just tired from looking at it.

 public class Practice {
 
  protected int    length ;
  protected Object[]  elements ;
 
  protected void resize(int n) {
    Object[] newElements = new Object[n] ;
    for (int i = 0 ; i < length ; i++) { newElements[i] = elements[i] ; }
    length = n ;
    elements = newElements ;
  }
 
  public Practice(int n) {
    length = n ;
    elements = new Object[n] ;
  }
 
  public void setElement(int i, Object obj) {
    if ( i >= length ) { resize(i+1) ; }
    elements[i] = obj ;
  }
 
  public Object getElement(int i) {
    return elements[i] ;
  }
 
  public int length() {
    return length ;
  }
 
  public String toString() {
    String result = "" ;
    for (int i = 0 ; i < length ; i++) { result = result + elements[i] + " " ; }
    return result ;
  }
 
} 

 public class Stuff extends Practice {
 
        public Stuff(){
                super(0);
        }
 
          public void push(Object n){
                int position = length;
                setElement(position,n);}
 
 
        public Object pop(){
                Object result = getElement(length-1);
                return result;}
 
        public boolean isEmpty(){
                return false;}
} 

 public class Test {
 
         public static void main(String[] args) {
                Stuff z = new Stuff() ;
                z.push("this") ;
                z.push("is") ;
                z.push("test") ;
                z.push("code") ;
                while ( !z.isEmpty() ) { System.out.println( z.pop() ) ; }
  }
 } 

[ April 14, 2005: Message edited by: MP Olsen ]

[Ta Ri Ki Sun]

Originally posted by MP Olsen:
In my "Stuff" class, my pop method needs to decrement by one each time subtracting the last word and returning it to be printed.

All it does at present is return the last value, the elements are never removed, so your while loop on isEmpty will always be false, even after you fix the method so it doesn't only return false.
Soooo, start with that, fix isEmpty, pop should remove an element.
I haven't looked at the rest but that might be it, feel free to ask again

[Ben Wood]

maybe this is for an assignment where you have been told to use an array...

 
Object[]
 

if you are not required to use an array, consider something from the Collections API, it will make your life easier.

For example, java.util.ArrayList has a remove() method that might be useful to you.