Stream Vs. Iterator in entrySet of a Map - Java 8

Question

To my understanding, the following code should have print true, since both Stream and Iterator are pointing to the first element.

Answer 1

The thing is:

Map.Entry entry1 = set.iterator().next();
Map.Entry entry2 = set.stream().findFirst().get();

You are not comparing the values you put into the map. But Entry objects!

In other words: it looks like your code is creating new Entry objects using your code. It is completely up to the internal implementation of that unmodifiable Map/Set what to return when it is asked for an iterator or a stream ... and as Eran was a bit quicker to lookup: the reason is that new Entry objects are created when iterating.

So, when using equals() instead of == ... you get the expected output.