Quiz on Data Structures in java

What will be displayed as output when a value not in an array is printed ?

 class Data {

public static void main ( String args [ ] ) 

{

int arr[] = new int[10];

for(int i = 0; i<arr.length;i++)

{

System.out.println(“DataFlair”);

}

}

}

class DataStructure {

public static void main ( String args [ ] )

{

LinkedList<int> l = new LinkedList<String>();

l.add(“DataFlair”);

System.out.println(l);

}

}

Which data structure in Java is recursive in nature ?

class StackDemo {

public static void main ( String args [ ] )

{

Stack<String> s = new Stack<String> ();

s.push(“One”);

s.push(“Two”);

s.push(“Three”);

System.out.println(s.peek());

}

}

class QueueDemo {

public static void main ( String args [ ] )

{

Queue<integer> q = new LinkedList<integer> ();

q.add(100);

q.add(99);

q.add(98);

q.add(97);

q.add(96);

System.out.println(q.size());

}

}

If A is the name of a Queue in Java, which of the following is the correct syntax to add a 

    element to this queue ?

class LinkedListDemo {

public static void main ( String args [ ] )

{

LinkedList<Long> l = new LinkedList<Long> ();

l.add(“641044”);

l.add(“641037”);

System.out.println(l.getLast());

}

}

class StackDataStructure {

public static void main ( String args [ ] )

{

Stack s = new Stack();

s.push(1);

s.push(1);

s.push(2);

s.push(3);

s.push(5);

s.push(8);

s.push(13);

s.push(21);

if(s.size()>5) {

s.clear();

}

if(s.empty==true) {

System.out.println(“Stack is empty”);

}

else {

System.out.println(“Stack is full”);

}

}

}

What is the function of the void clear ( ) method while using LinkedLists ?

 class QueueJava {

public static void main ( String args [ ] )

{

Queue<Integer> data = new Queue<Integer> ();

data.add(1);

data.add(2);

data.add(3);

int deleted = data.remove();

System.out.println(“Removed element is “ + deleted);

}

}

class PriorityQueue {

public static void main ( String args [ ] )

{

Queue<Integer> q = new PriorityQueue<Integer> ();

q.add(10);

q.add(3);

q.add(45);

q.add(7);

q.add(18);

System.out.println(q);

}

}

 Which of the following operations is used to remove a top element in a stack ?

class Array {

public static void main ( String args [ ] )

{

String Array[ ] = { “welcome” , “to” , “DataFlair” , “WebServices” };

for( int i = 0 ; i<= Array.length ; i ++ )

{

System.out.println(Array);

}

}

Class Function {

public static void main ( String args [ ] )

{

Stack<String> s = new Stack<String> ();

s.push(“DataFlair”);

s.push(“WebServices”);

s.push(“private”);

s.push(“limited”);

System.out.println(s);

s.pop();

s.pop();

System.out.println(s);

}

}