Linked Hashmap Program in Java

Basic Linked HashMap Operations

package com.java2novice.linkedhashmap;

import java.util.LinkedHashMap;

public class BasicLinkedHashMap

{

public static void main(String a[])

{

    LinkedHashMap lhm = new LinkedHashMap();

        lhm.put("one", "This is first element");

        lhm.put("two", "This is second element");

        lhm.put("four", "this element inserted at 3rd position");

        System.out.println(lhm);

        System.out.println("Getting value for key 'one': "+lhm.get("one"));

        System.out.println("Size of the map: "+lhm.size());

        System.out.println("Is map empty? "+lhm.isEmpty());

        System.out.println("Contains key 'two'? "+lhm.containsKey("two"));

        System.out.println("Contains value 'This is first element'? "

        +lhm.containsValue("This is first element"));

        System.out.println("delete element 'one': "+lhm.remove("one"));

        System.out.println(lhm);

    }

}

How to iterate through Linked HashMap

package com.java2novice.linkedhashmap;

import java.util.LinkedHashMap;

import java.util.Set;

public class MyMapIterate

{

public static void main(String a[])

{

        LinkedHashMap lhm = new LinkedHashMap();

        lhm.put("one", "This is first element");

        lhm.put("two", "This is second element");

        lhm.put("four", "Element inserted at 3rd position");

        Set keys = lhm.keySet();

        for(String k:keys)

        {

            System.out.println(k+" -- "+lhm.get(k));

        }

    }

}

How to check whether the value exists or not in a Linked HashMap

package com.java2novice.linkedhashmap;

import java.util.LinkedHashMap;

public class MyMapValueCheck

{

public static void main(String a[])

{

        LinkedHashMap lhm = new LinkedHashMap();

        lhm.put("one", "This is first element");

        lhm.put("two", "This is second element");

        lhm.put("four", "Element inserted at 3rd position");

        System.out.println("Map contains value 'This is first element'? "

         +lhm.containsValue("This is first element"));

    }

}

How to delete all entries from Linked HashMap object

package com.java2novice.linkedhashmap;

import java.util.LinkedHashMap;

public class MyMapClear

{

public static void main(String a[])

{

        LinkedHashMap lhm = new LinkedHashMap();

        lhm.put("one", "This is first element");

        lhm.put("two", "This is second element");

        lhm.put("four", "Element inserted at 3rd position");

        System.out.println(lhm);

        lhm.clear();

        System.out.println(lhm);

    }

}