Best way to convert an ArrayList to a string

Answer 1

If you don't want the last \t after the last element, you have to use the index to check, but remember that this only "works" (i.e. is O(n)) when lists implements the RandomAccess.

List list = new ArrayList();
list.add("one");
list.add("two");
list.add("three");

StringBuilder sb = new StringBuilder(list.size() * apprAvg); // every apprAvg > 1 is better than none
for (int i = 0; i < list.size(); i++) {
    sb.append(list.get(i));
    if (i < list.size() - 1) {
        sb.append("\t");
    }
}
System.out.println(sb.toString());