Maximum method for UnorderedArrayList

Question

I have created the following method in UnorderedArrayList but am having problems calling it from a test class to show that the method works.
public class UnorderedArrayList<T> extends ArrayListClass<T>
  public <T extends Comparable<T> > int maximum()
    int maxLoc = 0;
    if (length == 0)
      System.out.println("No items in the list.");//return null;  // if no items have been put in list, return null
    else
      for (int loc = 1; loc < length - 1; loc++)  // loop through items in list
        if (larger((T)list[maxLoc], (T)list[loc])== (T)list[loc])  // if larger returns the current item, set maxLoc to current location
          maxLoc = loc;  //max = (T)list[loc];
      return maxLoc;
public class test
UnorderedArrayList<Integer> UAL3 = new UnorderedArrayList<Integer>(5);
UAL3.insertAt(0, 30);
UAL3.insertAt(1, 3);
UAL3.insertAt(2, 70);
UAL3.insertAt(3, 65);
UAL3.insertAt(4, 34);
System.out.println("Original list:");
UAL3.print();
System.out.println("Max: " + UAL3.list[UAL3.maximum()]);On this second part, I am receiving the error:
test.java:56: incompatible types; inferred type argument(s) java.lang.Object do not conform to bounds of type variable(s) T
found : <T>int
required: int
               System.out.println("Max: " + UAL3.list[UAL3.maximum()]);
If I take out the <T extends Comparable<T> > in maximum, the call from test works but then the call to larger does not.
Any help would be appreciated. Thank you

Answer 1

If I take out the < T extends Comparable<T> > in
maximum, the call from test works but then the call
to larger does not.You'll have to remove one return type. Either return a T (without the extends stuff behind it) or return an int.
You could try this (untested!) code:public class UnorderedArrayList< T extends Comparable <T> > extends ArrayListClass<T> {
    public T maximum() {       
        if (length == 0) {
            return null;
        T max = list[0];
        for (int i = 1; i < length-1; i++) {
            T temp = list;
if (max.compareTo(temp) < 0) {
max = temp;
return max;
Checkout this tutorial on generics:
http://java.sun.com/j2se/1.5/pdf/generics-tutorial.pdf