JAVA EE: Java : Collection Framework : Hashtable (entryset)

Wednesday, 4 March 2015

Java : Collection Framework : Hashtable (entryset)

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https://www.youtube.com/watch?v=PDlqAxWAGlU&list=UUhwKlOVR041tngjerWxVccw

HashtableExample.java

import java.util.Hashtable;
import java.util.Map;
import java.util.Set;

/*
 * Example of entrySet() method.
 */
public class HashtableExample
{
    public static void main(String[] args)
    {

        Hashtable<String, String> hashtable = new Hashtable<String, String>();

        /*
         * Key = CountryCode,Value = CountryName.
         */
        hashtable.put("AF", "AFGHANISTAN");
        hashtable.put("BE", "BELGIUM");
        hashtable.put("US", "UNITED STATES");
        hashtable.put("IN", "INDIA");

        System.out.println("hashtable : " + hashtable + "\n");

        /*
         * A map entry (key-value pair).
         * 
         * Returns a Set view of the mappings contained in this map.
         */
        Set<Map.Entry<String, String>> entrySet = hashtable.entrySet();

        System.out.println("entrySet : " + entrySet + "\n");

        System.out.println("-----------------------");
        System.out.println("Key" + " | " + "value");
        System.out.println("-----------------------");

        for (Map.Entry<String, String> entry : entrySet)
        {
            String key = entry.getKey();
            String value = entry.getValue();
            System.out.println(key + "   | " + value);
        }
    }
}

Output

hashtable : {IN=INDIA, AF=AFGHANISTAN, BE=BELGIUM, US=UNITED STATES}

entrySet : [IN=INDIA, AF=AFGHANISTAN, BE=BELGIUM, US=UNITED STATES]

-----------------------
Key | value
-----------------------
IN   | INDIA
AF   | AFGHANISTAN
BE   | BELGIUM
US   | UNITED STATES