Question

I have the following code:

LinkedHashMap<String,ArrayList<String>> h;
Set set = h.entrySet();     
Iterator i = set.iterator();
        while(i.hasNext()) {
            System.out.println(i.next());
            Map.Entry me = (Map.Entry)i.next();
            String currentSegString = (String) me.getKey();

            System.out.println(currentKey+"**************");
        }

Prints out this:

1=[]
2**************
3=[A, B, C]
4**************
5=[]

But then I remove one line System.out.println(i.next());:

LinkedHashMap<String,ArrayList<String>> h;
Set set = h.entrySet();     
Iterator i = set.iterator();
        while(i.hasNext()) {

            Map.Entry me = (Map.Entry)i.next();
            String currentSegString = (String) me.getKey();

            System.out.println(currentKey+"**************");
        }

And it prints out this:

1**************
2**************
3**************
4**************
5**************

Why doesn’t it print ************** in the first case for each key?

Answer 1

That is because when you do :

System.out.println(i.next());

You are skipping to the next line, and then the Map also does .next()

Therefor you are only seeing 2 out of the possible 5 lines.

Explanation:

     while(i.hasNext()) { 
        System.out.println(i.next()); //skip one  #1, #3, #5
        Map.Entry me = (Map.Entry)i.next(); //goto next one #2, #4
        String currentSegString = (String) me.getKey();

        System.out.println(currentKey+"**************"); //output #2,4
    }

Second code:

    while(i.hasNext()) {

        Map.Entry me = (Map.Entry)i.next(); //goto next one #1, #2, #3, #4, #5
        String currentSegString = (String) me.getKey();

        System.out.println(currentKey+"**************"); //output #1,2,3,4,5
    }

A way to fix this would be:

    while(i.hasNext()) {
        Object temp = i.next(); //goto next one #1, #2, #3, #4, #5
        System.out.println(temp);
        Map.Entry me = (Map.Entry)temp; 
        String currentSegString = (String) me.getKey();

        System.out.println(currentKey+"**************"); //output #1,2,3,4,5
    }