Why did iterator not work but for-each did?

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I have already completed the task, but I was wondering why when I used iterator it did not iterate over the map and only checked if the first value in the map was repeated, while the for-each checked all values of the map to see if they were repeated and was able to complete the task. Since I completed the task I can't attach my code but I will just paste the iterator part I was talking about. Thank You! Iterator: HashMap<String, String> copy1 = new HashMap<String, String>(map); HashMap<String, String> copy2 = new HashMap<String, String>(map); Iterator<Map.Entry<String, String>> iterator = copy1.entrySet().iterator(); Iterator<Map.Entry<String, String>> iterator1 = copy2.entrySet().iterator(); String v; while (iterator.hasNext()) { v = iterator.next().getValue(); int count = 0; while (iterator1.hasNext()) { if (iterator1.next().getValue().equals(v)) count++; if (count > 1) { removeItemFromMapByValue(map, v); } } }

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Guadalupe Gagnon

Level 37 , Tampa, United States

27 December 2018, 20:14

You never reset the values in iterator1. if you step through the code:

// ↓ set iterators with these two lines of code
Iterator<Map.Entry<String, String>> iterator = copy1.entrySet().iterator();
Iterator<Map.Entry<String, String>> iterator1 = copy2.entrySet().iterator();
String v;
// ↓pulls first value of copy1
while (iterator.hasNext()) {
   v = iterator.next().getValue();
   int count = 0;
   // ↓ pulls all values in copy two on first pass through
   while (iterator1.hasNext()) {
      if (iterator1.next().getValue().equals(v)) count++;
      // on second pass through it would not have any values
         ...
         ......
      }
}

the foreach loop like this

for(......:copy1.entryset()){
    for(.....:copy2.entryset()){ // this is a new loop every time the outer loop cycles
     /* code to execute */
    }
}

Guadalupe Gagnon

Level 37 , Tampa, United States

27 December 2018, 20:16

You would have to make your iterator look like this:

while (iterator.hasNext()) {
   v = iterator.next().getValue();
   int count = 0;
   iterator1 = copy2.entrySet().iterator(); // add this line of code
   while (iterator1.hasNext()) {
      if (iterator1.next().getValue().equals(v)) count++;
         ...
         ......
      }
}

Will Rosenberg

Level 9 , Glendale, United States

27 December 2018, 20:41

Ok. This makes a lot of sense thank you.