Java: Iterating through the Map

This example demonstrates different way of iterating or looping through a Map-HashMap. Folling topics are covered

1. Iterating through the Map using iterator
2. Iterating through the Map keys
3. Iterating through the Map values
4. Iterating using a for loop

public class MapIteration

{

public static void main(String[] args)

{

Map<Integer, String> map = new HashMap<Integer, String>();

map.put(1, "Jan");

map.put(2, "Feb");

map.put(3, "Mar");

map.put(4, "Apr");

map.put(5, "May");

map.put(6, "Jun");

Iterator<Entry<Integer, String>> iter = map.entrySet().iterator();

while (iter.hasNext())

{

Map.Entry<Integer, String> mapEntry = (Map.Entry<Integer, String>) iter.next();

System.out.println("Key: " + mapEntry.getKey() + ", Value :" + mapEntry.getValue());

}

for (Map.Entry<Integer, String> entry : map.entrySet())

{

System.out.println("Key : " + entry.getKey() + " Value : " + entry.getValue());

}

Iterator keysIter = map.keySet().iterator();

while (keysIter.hasNext())

{

Integer key = (Integer) keysIter.next();

System.out.println("Key: " + key);

}

for (String value : map.values())

{

System.out.println("Value : " + value);

}

}

}