Changing data in a linked list object.

Question

hi,
i'm still pretty new to java, so bear with me if i am making stupid mistakes, heh.
i'm having trouble with changing data in an object stored in a singly-linked list. i've created a class that will store polynomials in sorted order (descending) in a singly-linked list. each linked list is one polynomial, and each node references to a polynomial object that stores two ints: the coefficient and the exponent of that term.
i'm having trouble when it comes to 'collecting like terms,' though. here's a rough skeleton of my code:
public class Polynomial
private LinkedList polynoList;
private LinkedListItr Itr;
private int coeff;
private int exponent;
public Polynomial()
zeroPolynomial();
} // this constructor sets up an empty linked list
public Polynomial( int c, int e )
coeff = c;
exponent = e;
} // this creates a Polynomial object storing the two ints
public void zeroPolynomial()
polynoList = new LinkedList();
theItr = polynoList.zeroth();
} // this method creates the empty linked list and sets the
//iterator on the zeroth node.
//various other methods are here, not relevant to my post
//this next method is the one i am having trouble with.
//it takes two ints as parameters, the coefficient
//and the exponent.
public void insertTerm( int c, int e )
//...i have a few if/then statements here
//so that the terms can be inserted in descending order.
LinkedListItr tester = polynoList.first();
//the 'tester' iterator is set on the first node
//this following if statement retrieves the exponent
//in the current node by casting the information
//retrieved from the LinkedList retrieve() method
//into Polynomial, then compares it to the current
//exponent. if they are equal, i want to add the
//coefficients.
if( e == ((Polynomial)tester.retrieve()).getExp() )
this.coeff = ((Polynomial)tester.retrieve()).getCoeff() + c;
//a main method goes here wherein the user can insert
//terms, print the polynomial, etc.
}//end Polynomial class
can anyone help me out? the code i'm using compiles correctly, but it does not change the value of the current coeff variable as i'd like to think it should. any input would be GREATLY appreciated, thanks!

Answer 1

hey,
thanks for the reply...
i am sure that ((Polynomial)tester.retrieve()).getExp() will return an int equal to 'e.' i tried this:
System.out.println("e="+e);
System.out.println((Polynomial)tester.retrieve()).getExp());
if( e == ((Polynomial)tester.retrieve()).getExp() ){
this.coeff = ((Polynomial)tester.retrieve()).getCoeff() + c;
System.out.println( "this.coeff = " + this.coeff );
with that, the output showed that e and the getExp() output were the same. it also showed (as output) that this.coeff did change in value, but when i tried this:
System.out.println( ((Polynomial)tester.retrieve()).getCoeff() )
to check if the value changed within the object, it didn't. this.coeff changed, but the actual coeff variable in the object didn't.
any ideas?