Question

Im trying to change the sort method in the following code to sort objects of any type rather than just string but a bit stumped, all advice welcome.

class SortNames {

static void sort(String[] s) {
    for (int i = 0; i<s.length; i++) {
        for (int j = i+1; j < s.length; j++) {
            if (s[i].compareTo(s[j])>0) {
                String t;
                t = s[i]; s[i] = s[j]; s[j] = t;
            }
        }
    }
}

public static void main(String[] args) {
    String[] names = {"Pete","Jill","May","Anne","Tim"};             
    sort(names);
    for (int i=0; i<names.length; i++) 
        System.out.println(names[i]);
}
}

Answer 1

Turn SortNames into SortNames<T extends Comparable<? super T>>, and change String[] to T[], which is how Collections.sort() work:

public class SortNames<T extends Comparable<? super T>> {
    public void sort(T[] s) {
        for (int i = 0; i<s.length; i++) {
            for (int j = i+1; j < s.length; j++) {
                if (s[i].compareTo(s[j])>0) {
                    T t = s[i]; s[i] = s[j]; s[j] = t;
                }
            }
        }
    }
    // or static <T extends Comparable<? super T>> void, for static methods
}