iterating through hashmaps and accessing its elements

Question

I want to iterate through a hashmap. I know I can easily use the entrySet. But the problem is I want to access two elements at once.

example:

HasHMap<Integer,Point> myMap = new HashMap<Integer,Point>();
          //I add some points to the map where integer is the id of that point

I want to be able to access two elements at once so I can use the Graphics drawLine method.

I'm not sure if there's a way.

NOTE: I'm using a hashmap because it is easy to find any point by its id as my map has its polygons made from list of ids.

possible duplicate of [Iterate over each Entry in a Map](http://stackoverflow.com/questions/46898/iterate-over-each-entry-in-a-map) — GreenMatt, Nov 22 '14 at 03:38
Every pair of two points? Or just two specific points? You _can_ call `myMap.get` more than once. — Louis Wasserman, Nov 22 '14 at 04:08
yes iterate through every pair of two points. @LouisWasserman — Moe, Nov 22 '14 at 05:47

MeBigFatGuy · Accepted Answer · 2014-11-22T04:14:45.537

0

Just have a separate Map.Entry variable that you set inside the loop. Then you can use drawTo using this variable and the loop variable.

Map.Entry<?, ?> oldValue = null;
for(Map.Entry<?, ?> newValue : values) {
   if (oldValue != null) {
      doSomethingWithBoth(oldValue, newValue);
   }
   oldValue = newValue;
}

I dont' know what kind of variables you are using thus the ?.... You should put the type you are using there.

edited Nov 22 '14 at 04:14

answered Nov 22 '14 at 03:39

MeBigFatGuy

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This works perfectly. although it took me a bit to understand its logic. Thanks. Great logic behind this work. – Moe Nov 22 '14 at 05:58

iterating through hashmaps and accessing its elements

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