In this example we shall show you how to obtain a Hashtable keys Iterator, that is an iterator of the keys of the Hashtable. To obtain a Hashtable keys Iterator one should perform the following steps:
- Create a new Hashtable.
- Populate the hashtable with elements, using
put(K key, V value)API method of Hashtable. - Invoke
keys()API method of Hashtable. It returns an Enumeration of the keys contained in the Hashtable. - Iterate through the enumeration, with
hasMoreElements()andnextElement()API method of Enumeration,
as described in the code snippet below.
package com.javacodegeeks.snippets.core;
import java.util.Hashtable;
import java.util.Enumeration;
public class HashtableKeysIterator {
public static void main(String[] args) {
// Create a Hashtable and populate it with elements
Hashtable hashtable = new Hashtable();
hashtable.put("key_1","value_1");
hashtable.put("key_2","value_2");
hashtable.put("key_3","value_3");
// Enumeration keys() operation returns an Enumeration of keys contained in Hashtable
Enumeration keysEnumeration = hashtable.keys();
// Iterate through Hashtable keys Enumeration
System.out.println("Hashtable keys : ");
while(keysEnumeration.hasMoreElements())
System.out.println(keysEnumeration.nextElement());
}
}
Output:
Hashtable keys :
key_3
key_2
key_1
This was an example of how to obtain a Hashtable keys Iterator in Java.
