Calling iterator.next() through a TreeSet [example from Thinking In Java]

Question

Reading Containers in Depth chapter from the Thinking In Java book. Saw this example(modified from SortedMapDemo.java):

 TreeSet<String> sortedSet = new TreeSet<String>(); 
 Collections.addAll(sortedSet,
           "a b c d e f g h"
             .split(" "));
...
Iterator<String> it = sortedSet.iterator();
for(int i = 0; i <= 6; i++) {
  if(i == 3) low = it.next();
  if(i == 6) high = it.next();
  else it.next();
}
print(low);
print(high); //overridden 

What baffles me is that while 'low' prints out "d", 'high' prints out "h", for which I think should be "g" instead.
If we're calling it.next() in each iteration, shouldn't the 7th iteration gives "g"??

Answer 1

You have an if followed by an if/else . So the iteration occurs twice when i == 3 . Here is your original code re-written with braces and spacing for clarity:

if (i == 3) {
    low = it.next();
}

if (i == 6) {
    high = it.next();
} else {
    it.next();
}

This would give you expected results:

if(i == 3) low = it.next();
else if(i == 6) high = it.next();
else it.next();