HashMap
HashMap Iterator example
In this example we shall show you how to use a HashMap Iterator. To use a HashMap one should perform the following steps:
- Create a new HashMap.
- Populate the hashMap with elements, with the
put(K key, V value)
API method of HashMap. - Invoke the
entrySet()
API method of the HashMap to get a Set of all the entries (key – value pairs) contained in the HashMap. - Obtain an Iterator for the entries Set, and iterate through the HashMap entries,
as described in the code snippet below.
package com.javacodegeeks.snippets.core; import java.util.HashMap; import java.util.Iterator; import java.util.Set; public class HashMapIterator { public static void main(String[] args) { // Create a HashMap and populate it with elements HashMap hashMap = new HashMap(); hashMap.put("key_1","value_1"); hashMap.put("key_2","value_2"); hashMap.put("key_3","value_3"); // Get a set of all the entries (key - value pairs) contained in the HashMap Set entrySet = hashMap.entrySet(); // Obtain an Iterator for the entries Set Iterator it = entrySet.iterator(); // Iterate through HashMap entries System.out.println("HashMap entries : "); while(it.hasNext()) System.out.println(it.next()); } }
Output:
HashMap entries :
key_3=value_3
key_2=value_2
key_1=value_1
This was an example of how to use a HashMap Iterator in Java.