Collections
- Which of these class object uses the key to store value?
-
View Hint View Answer Discuss in Forum
NA
Correct Option: D
Dictionary, Map & Hashtable all implement Map interface hence all of them uses keys to store value in the object.
- What is the output of this program?
import java.util.*;
public class stack_Example
{
public static void main(String args[])
{
Stack object = new Stack();
object.push(new Integer(20));
object.push(new Integer(12));
object.pop();
object.push(new Integer(60));
System.out.println(object);
}
}
-
View Hint View Answer Discuss in Forum
NA
Correct Option: A
push() and pop() are standard functions of the class stack, push() inserts in the stack and pop removes from the stack. 20 & 12 are inserted using push() the pop() is used which removes 12 from the stack then again push is used to insert 60 hence stack contains elements 20 & 60.
- What is the output of this program?
import java.util.*;
public class vector_Example
{
public static void main(String args[])
{
Vector object = new Vector(6,3);
object.addElement(new Integer(10));
object.addElement(new Integer(20));
object.addElement(new Integer(50));
object.removeAll(object);
System.out.println(object.isEmpty());
}
}
-
View Hint View Answer Discuss in Forum
NA
Correct Option: A
firstly elements 10, 20, 50 are entered in the vector object, but when object.removeAll(object); is executed all the elements are deleted and vector is empty, hence object.isEmpty() returns true.
- What is the output of this program?
import java.util.*;
public class vector_Example
{
public static void main(String args[])
{
Vector object = new Vector(6,3);
object.addElement(new Integer(10));
object.addElement(new Integer(20));
object.addElement(new Integer(60));
object.insertElementAt(new Integer(80), 1);
System.out.println(object);
}
}
-
View Hint View Answer Discuss in Forum
NA
Correct Option: E
[10, 80, 20, 60]
- What is the output of this program?
import java.util.*;
public class vector
{
public static void main(String args[])
{
Vector object = new Vector(6,3);
object.addElement(new Integer(9));
object.addElement(new Integer(7));
object.addElement(new Integer(3));
System.out.println(object.capacity());
}
}
-
View Hint View Answer Discuss in Forum
NA
Correct Option: B
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