41. What will be the output of the following Java program?
import java.util.*;
public class genericstack <E>
{
Stack <E> stk = new Stack <E>();
public void push(E obj)
{
stk.push(obj);
}
public E pop()
{
E obj = stk.pop();
return obj;
}
}
class Output
{
public static void main(String args[])
{
genericstack <Integer> gs = new genericstack<Integer>();
gs.push(36);
System.out.println(gs.pop());
}
}
import java.util.*;
public class genericstack <E>
{
Stack <E> stk = new Stack <E>();
public void push(E obj)
{
stk.push(obj);
}
public E pop()
{
E obj = stk.pop();
return obj;
}
}
class Output
{
public static void main(String args[])
{
genericstack <Integer> gs = new genericstack<Integer>();
gs.push(36);
System.out.println(gs.pop());
}
}
42. What will be the output of the following Java program?
import java.util.*;
public class genericstack <E>
{
Stack <E> stk = new Stack <E>();
public void push(E obj)
{
stk.push(obj);
}
public E pop()
{
E obj = stk.pop();
return obj;
}
}
class Output
{
public static void main(String args[])
{
genericstack <Integer> gs = new genericstack<Integer>();
gs.push(36);
System.out.println(gs.pop());
}
}
import java.util.*;
public class genericstack <E>
{
Stack <E> stk = new Stack <E>();
public void push(E obj)
{
stk.push(obj);
}
public E pop()
{
E obj = stk.pop();
return obj;
}
}
class Output
{
public static void main(String args[])
{
genericstack <Integer> gs = new genericstack<Integer>();
gs.push(36);
System.out.println(gs.pop());
}
}
43. Which of these is wildcard symbol?
44. What will be the output of the following Java program?
import java.util.*;
class Output
{
public static void addNumbers(List<? super Integer> list)
{
for (int i = 1; i <= 10; i++)
{
list.add(i);
}
}
public static void main(String args[])
{
List<Double> ld = Arrays.asList();
addnumbers(10.4);
System.out.println("getList(2)");
}
}
import java.util.*;
class Output
{
public static void addNumbers(List<? super Integer> list)
{
for (int i = 1; i <= 10; i++)
{
list.add(i);
}
}
public static void main(String args[])
{
List<Double> ld = Arrays.asList();
addnumbers(10.4);
System.out.println("getList(2)");
}
}
45. Which of these is an correct way making a list that is upper bounded by class Number?
46. What will be the output of the following Java program?
public class BoxDemo
{
public static <U> void addBox(U u,
java.util.List<Box<U>> boxes)
{
Box<U> box = new Box<>();
box.set(u);
boxes.add(box);
}
public static <U> void outputBoxes(java.util.List<Box<U>> boxes)
{
int counter = 0;
for (Box<U> box: boxes)
{
U boxContents = box.get();
System.out.println("Box #" + counter + " contains [" + boxContents.toString() + "]");
counter++;
}
}
public static void main(String[] args)
{
java.util.ArrayList<Box<Integer>> listOfIntegerBoxes = new java.util.ArrayList<>();
BoxDemo.<Integer>addBox(Integer.valueOf(10), listOfIntegerBoxes);
BoxDemo.outputBoxes(listOfIntegerBoxes);
}
}
public class BoxDemo
{
public static <U> void addBox(U u,
java.util.List<Box<U>> boxes)
{
Box<U> box = new Box<>();
box.set(u);
boxes.add(box);
}
public static <U> void outputBoxes(java.util.List<Box<U>> boxes)
{
int counter = 0;
for (Box<U> box: boxes)
{
U boxContents = box.get();
System.out.println("Box #" + counter + " contains [" + boxContents.toString() + "]");
counter++;
}
}
public static void main(String[] args)
{
java.util.ArrayList<Box<Integer>> listOfIntegerBoxes = new java.util.ArrayList<>();
BoxDemo.<Integer>addBox(Integer.valueOf(10), listOfIntegerBoxes);
BoxDemo.outputBoxes(listOfIntegerBoxes);
}
}
47. What will be the output of the following Java code?
import java.util.*;
public class genericstack <E>
{
Stack <E> stk = new Stack <E>();
public void push(E obj)
{
stk.push(obj);
}
public E pop()
{
E obj = stk.pop();
return obj;
}
}
class Output
{
public static void main(String args[])
{
genericstack <Integer> gs = new genericstack<Integer>();
gs.push(36);
System.out.println(gs.pop());
}
}
import java.util.*;
public class genericstack <E>
{
Stack <E> stk = new Stack <E>();
public void push(E obj)
{
stk.push(obj);
}
public E pop()
{
E obj = stk.pop();
return obj;
}
}
class Output
{
public static void main(String args[])
{
genericstack <Integer> gs = new genericstack<Integer>();
gs.push(36);
System.out.println(gs.pop());
}
}
48. Which of these type parameters is used for a generic methods to return and accept a number?
49. Which of the following cannot be Type parameterized?
50. What will be the output of the following Java program?
import java.util.*;
class Output
{
public static double sumOfList(List<? extends Number> list)
{
double s = 0.0;
for (Number n : list)
s += n.doubleValue();
return s;
}
public static void main(String args[])
{
List<Integer> li = Arrays.asList(1, 2, 3);
System.out.println(sumOfList(li));
}
}
import java.util.*;
class Output
{
public static double sumOfList(List<? extends Number> list)
{
double s = 0.0;
for (Number n : list)
s += n.doubleValue();
return s;
}
public static void main(String args[])
{
List<Integer> li = Arrays.asList(1, 2, 3);
System.out.println(sumOfList(li));
}
}