Question

I want to remove strings of length 5 from a set, but it keeps outputting the set itself.

public void remove5()
{
Set<String> newSet = new HashSet<String>();
newSet.add("hello");
newSet.add("my");
newSet.add("name");
newSet.add("is");
newSet.add("nonsense");
for(String word: newSet)
{
    if(word.length()==5)
    {
        newSet.remove(word); // Doesn't Help - throws an error Exception in thread "main" java.util.ConcurrentModificationException
    }
}
    System.out.println(newSet);
}

I want the output to be:

my
name
is
nonsense

(hello was removed because it’s 5 characters)

But I get this everytime:

hello
my
name
is 
nonsense

Can you please help?

Answer 1

Iterator<String> it= newStr.iterator();
while(it.hasNext()) { // iterate
   String word = it.next();
   if(word.length() == 5) { // predicate
      it.remove();  // remove from set through iterator - action
   }
}