Free Java Quiz Questions With Answers – Prepare Yourself For Interviews

import java. util.Arrays; 
import java. util.Comparator;
class Sorting implements Comparator
{ 
    public int compare(Integer o1, Integer o2)
    {
        return o2. compareTo(o1);
    }
}
public class abc {
     public static void main (String...a)
     {
         Integer intArray[]= {2,3,1};
         Arrays.sort(intArray, new Sorting()); 
         for(int i: intArray)
             {
             System. out. print(i+"");
             }
     }
}

import java.util.Iterator;
import java.util.Set;
import java.util.TreeSet;

public class ConcurrentSkipListMapTest {
	 public static void main (String args)
	 {
		 Set set = new TreeSet();
		 set.add(1);
		 set.add("2");
		 set.add(3);
		 
		 Iterator iterator = set.iterator();
		 while (iterator. hasNext())
		 {
			 System. out. print(iterator. next()+"");
		 }
	 }

}

import java.util.ArrayList;
import java.util. Iterator;
import java.util. List;

public class ArrayListTest {
	public static void main (String args[])
	{
		List arrayList = new ArrayList();
		
		arrayList.add("a"); 
		arrayList.add("b");
		
		Iterator iterator = arrayList.iterator(); 
		
		while (iterator.hasNext()) 
		{
			System.out.println(iterator.next());
			arrayList.add("c");
		}
	}
}

import java.util.ArrayList;
import java.util.Collections; 
import java.util.Comparator; 

class Employee { 
	String name; 
	public Employee() {}
	public Employee (String name) { 
		this.name = name;
	}
	public String toString()
	{
		return "name=" + name;
	}
	static class ComparatorName implements Comparator
	{
		public int compare (Employee obj1, Employee obj2) 
	{
		return obj1.name.compareTo(obj2.name);
	}
	
	}
}
public class ComparatorUsageDemo {
	  public static void main (String[] args)
	  {
		  Employee emp1 =new Employee("ankit"); 
		  Employee emp2= new Employee("brad");
		  
		  ArrayList list=new ArrayList();
		  {
			  list.add(emp1);
			  list.add(emp2);
			  
			  Collections.sort(list,new Employee.ComparatorName());
			  System. out. println (list) ;  
		  }
		  		
	  }
}

import java.util.HashSet;
import java.util.Set;
public class HashSetTest 
{ 
	public static void main (String args[]) 
	{
		Set hashSet = new HashSet();
		hashSet.add("1");
		hashSet.add(1);
		hashSet.add(null);
		hashSet.add("null");
		System.out.println(hashSet);
}


}

import java.util.IdentityHashMap;
import java.util.Map;

	  public class MyClass 
	  { 
		  public static void main(String args[]) 
		  { 
			  Map identityHashMap = new IdentityHashMap();
			  identityHashMap.put(new String("a"),"audi");
			  identityHashMap.put(new String("a"),"ferrari");
			  System.out.println(identityHashMap);
	  }
}

import java.util.HashMap;
import java.util.Map;

	  public class MyClass 
	  { 
		  public static void main(String args[]) 
		  { 
			  Map hashMap = new HashMap();
			  hashMap.put(new String("a"),"audi");
			  hashMap.put(new String("a"),"ferrari");
			  System.out.println(hashMap);
	  }
}