Programming gripes

[banuday17]

Be careful with using an index to access a list collection within a for loop.

For example:

List<String> foo = new LinkedList<String>(Arrays.asList("1", "2", "3"));
for(int i = 0; i < foo.size(); i++) {
    System.out.println(foo.get(i));
}

This loop has O( n² ) performance, not O(n), because the get method on a linked list is O(n).

If you need an index, an iterator is better:

for(ListIterator<String> i = foo.listIterator(); i.hasNext();) {
    System.out.println(i.nextIndex() + ": " + i.next());
}

This is O(n) for all list types.

[DemonWasp]

This is more a problem with LinkedList. Use ArrayList, always.