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.
