How can I iterate over a string in Java?

Question

public static Boolean cmprStr( String s1, String s2 )
{
    // STUFF
}

I want to iterate through s1 to make sure that every character in s1 is incl

Answer 1

All the other answers are O(n^2). Here's a way that is linear in time (i.e. O(n)) using Google Guava:

  public static boolean cmprStr(String s1, String s2) {
    Set desiredCharacters = Sets.newHashSet(Lists.charactersOf(s2));
    return Sets.difference(Sets.newHashSet(Lists.charactersOf(s1)), desiredCharacters).isEmpty();
  }