Question 1 of 25
Hints left: 3
Q1
How to externally synchronize hashmap?
Q2
Which of these class is used for creating a client for a server-client operations?
Q3
Set has contains(Object o) method.
Q4
Which of these method is used to insert value and its key?
Q5
What is the unique feature of LinkedHashSet?
Q6
What happens if we put a key object in a HashMap which exists?
Q7
Which of these is the interface of legacy is implemented by Hashtable and Dictionary classes?
Q8
Which of these interface handle sequences?
Q9
If two threads access the same hashmap at the same time, what would happen?
Q10
Which of these class object can be used to form a dynamic array?
Q11
What will be the output of the following Java program? import java.util.*; class Array { public static void main(String args[]) { int array[] = new int [5]; for (int i = 5; i > 0; i--) array[5 - i] = i; Arrays.sort(array); for (int i = 0; i < 5; ++i) System.out.print(array[i]);; } }
Q12
What will be the output of the following Java code? import java.util.*; class vector { public static void main(String args[]) { Vector obj = new Vector(4,2); obj.addElement(new Integer(3)); obj.addElement(new Integer(2)); obj.addElement(new Integer(5)); System.out.println(obj.elementAt(1)); } }
Q13
Which of these methods can be used to obtain a static array from an ArrayList object?
Q14
Which of these methods can randomize all elements in a list?
Q15
What will be the output of the following Java program? import java.util.*; class Collection_Algos { public static void main(String args[]) { LinkedList list = new LinkedList(); list.add(new Integer(2)); list.add(new Integer(8)); list.add(new Integer(5)); list.add(new Integer(1)); Iterator i = list.iterator(); Collections.reverse(list); while(i.hasNext()) System.out.print(i.next() + " "); } }
Q16
Which of these method of Array class is used sort an array or its subset?
Q17
Which of these method is used to remove all keys/values pair from the invoking map?
Q18
What will be the output of the following Java program? import java.lang.reflect.*; class Additional_packages { public static void main(String args[]) { try { Class c = Class.forName("java.awt.Dimension"); Method methods[] = c.getMethods(); for (int i = 0; i < methods.length; i++) System.out.println(methods[i]); } catch (Exception e) { System.out.print("Exception"); } } }
Q19
Which of these package is used for remote method invocation?
Q20
What will be the output of the following Java program? import java.util.*; class Maps { public static void main(String args[]) { HashMap obj = new HashMap(); obj.put("A", new Integer(1)); obj.put("B", new Integer(2)); obj.put("C", new Integer(3)); System.out.println(obj); } }
Q21
What will be the output of the following Java program? import java.util.*; class Collection_iterators { public static void main(String args[]) { ListIterator a = list.listIterator(); if(a.previousIndex()! = -1) while(a.hasNext()) System.out.print(a.next() + " "); else System.out.print("EMPTY"); } }
Q22
What will be the output of the following Java code? import java.util.*; class stack { public static void main(String args[]) { Stack obj = new Stack(); obj.push(new Integer(3)); obj.push(new Integer(2)); obj.pop(); obj.push(new Integer(5)); System.out.println(obj); } }
Q23
What will be the output of the following Java code? import java.util.*; class hashtable { public static void main(String args[]) { Hashtable obj = new Hashtable(); obj.put("A", new Integer(3)); obj.put("B", new Integer(2)); obj.put("C", new Integer(8)); System.out.print(obj.toString()); } }
Q24
What will be the output of the following Java program? import java.util.*; class Arraylist { public static void main(String args[]) { ArrayList obj1 = new ArrayList(); ArrayList obj2 = new ArrayList(); obj1.add("A"); obj1.add("B"); obj2.add("A"); obj2.add(1, "B"); System.out.println(obj1.equals(obj2)); } }
Q25
Which of these class object uses the key to store value?