How to find the minimum value in an ArrayList, along with the index number? (Java)

Question

I need to get the index value of the minimum value in my arraylist in Java. MY arraylist holds several floats, and I'm trying to think of a way I can get the index number of the smallest float so I can use that index number elsewhere in my code. I'm a beginner, so please don't hate me. Thanks!

Answer 1

You can use Collections.min and List.indexOf:

int minIndex = list.indexOf(Collections.min(list)); 

If you want to traverse the list only once (the above may traverse it twice):

public static <T extends Comparable<T>> int findMinIndex(final List<T> xs) {     int minIndex;     if (xs.isEmpty()) {         minIndex = -1;     } else {         final ListIterator<T> itr = xs.listIterator();         T min = itr.next(); // first element as the current minimum         minIndex = itr.previousIndex();         while (itr.hasNext()) {             final T curr = itr.next();             if (curr.compareTo(min) < 0) {                 min = curr;                 minIndex = itr.previousIndex();             }         }     }     return minIndex; } 

Answer 2

This should do it using built in functions.

public static int minIndex (ArrayList<Float> list) {   return list.indexOf (Collections.min(list)); }