Java Collections Demo

package practice;

import java.util.*;

/* Collection - Arrays/Linked List/Hash Set's/Hash Map */

public class DemoCollection {

public static void main(String [] args) {

//ArrayList
List<String> a1 = new ArrayList<String>();
a1.add("Surendra");
a1.add("Sam");
a1.add("Steven");
a1.add("sam");
System.out.println("Array list ");
System.out.print("\t lenghth:" + a1.size()+ a1);

//Linkedlist
List <String> l1 = new LinkedList<String>();
l1.add("Suri");
l1.add("Sami");
l1.add("Stevie");
l1.add("Suri");
System.out.println();
System.out.println("Linked List");
System.out.print("\t"+l1);

//HashSet's
Set <Integer> s1 = new HashSet<Integer>();
s1.add(10);
s1.add(20);
System.out.println();
System.out.println("Hash Set");
System.out.print("\t"+s1);

//HashMap's
//Old method - Map<String,Integer> hm = new HashMap<String, Integer>();
HashMap<String,Integer> hm = new HashMap<String, Integer>();

//Put Method to insert Key->value
hm.put("Suri",47);
hm.put("Sam",16);
hm.put("Steve",30);

System.out.println("\nDisplaying Hashmap");
System.out.println("\t" + hm);

//Get - To get value of the specified key
int a = hm.get("Sam");
System.out.println();
System.out.println("\n HashMap Examples");
System.out.println("Getting value");
System.out.println(hm.get("Suri"));
System.out.println(a);

//Get All the Keys and Print
System.out.println("Printing All the Keys");
Set <String> keys = hm.keySet();
for (String key :keys) {
System.out.println(key);
}


}
}