And then fetch the floats with

Easy example:

1. ArrayList<Float> floats = new ArrayList<Float>();
2. 
   
3. void setup() {
4.   floats.add(1.6);
5.   floats.add(1.2);
6.   floats.add(2.5);
7. }
8. 
   
9. void draw() {
10.   for (int index = 0; index < floats.size(); index++)
11.     println(floats.get(index));
12. }

Everything in Java inherits from Object class (the primitive types have their corresponding classes like: float --> Float - see that bustup's example uses Float type, not float!!), so if not specified during list declaration as bustup showed, everything you put into ArrayList will be kept as an Object class instance*. You want to use it as some other type - you have to cast it.

BTW: there is a nice shorcut when working with arrays and ArrayLists called for each loop:

1. ArrayList<Float> list = new ArrayList<Float>();
2. list.add( 1.14 );
3. list.add( 2.14 );
4. list.add( 3.14 );
5. for( float f : list ) {
6.   // do sth with f
7. }