# Programming In Java | Week 3

Session: JULY-DEC 2023

Course Name: Programming In Java

### Programming Assignment

Question 1
This program is related to the generation of Fibonacci numbers.
For example: 0,1, 1,2, 3,5, 8, 13,… is a Fibonacci sequence where 13 is the 8th Fibonacci number.
A partial code is given and you have to complete the code as per the instruction given .

Solution:

``````if (n==1)      //Terminal condition
return 0;
else if(n==2)
return 1;
return fib(n - 1) + fib(n - 2); //Recursive call of function``````

Question 2
Define a class Point with two fields x and y each of type double. Also, define a method distance(Point p1, Point p2) to calculate the distance between points p1 and p2 and return the value in double.

Solution:

``````class Point{
double x;
double y;

public static void distance(Point p1,Point p2)
{
double d;
d=Math.sqrt((p2.x-p1.x)*(p2.x-p1.x) + (p2.y-p1.y)*(p2.y-p1.y));
System.out.print(d);
}
}``````

These are NPTEL Programming In Java Week 3 Assignment 3 Answers

Question 3
A class Shape is defined with two overloading constructors in it. Another class Test1 is partially defined which inherits the class Shape. The class Test1 should include two overloading constructors as appropriate for some object instantiation shown in main() method. You should define the constructors using the super class constructors. Also, override the method calculate( ) in Test1 to calculate the volume of a Shape.

Solution:

``````double height;
Test1(double length,double h) {
//base class constructor with one parameter is called
super(length);
height=h;
}

//base class constructor having two argument is called
height=h;
}

double calculate()	{
}``````

Question 4
This program to exercise the call of static and non-static methods. A partial code is given defining two methods, namely sum( ) and multiply ( ). You have to call these methods to find the sum and product of two numbers. Complete the code segment as instructed.

Solution:

``````QuestionScope st = new QuestionScope();
int result1=st.sum(n1,n2);
int result2=QuestionScope.multiply(n1,n2);

System.out.println(result1);
System.out.print(result2);``````

These are NPTEL Programming In Java Week 3 Assignment 3 Answers

Question 5
Complete the code segment to swap two numbers using call by object reference.

Solution:

``````public static void swap(Question t)
{
int temp = t.e1;
t.e1 = t.e2;
t.e2 = temp;
}``````

These are NPTEL Programming In Java Week 3 Assignment 3 Answers

Session: JAN-APR 2023

Course Name: Programming in Java

These are NPTEL Programming In Java Week 3 Assignment 3 Answers

#### Q1. Which of the following statement(s) is/are correct about the constructor?a. Constructors cannot be synchronized in Java.b. Java does not provide a default copy constructor.c. A constructor cannot be overloaded.d. “this” or “super” can be used in a constructor.

Q2. Which of the following statement(s) is/are true?
a. You can write a new instance method in the subclass with the same signature as the one in the superclass, thus overriding it.
b. You can write a new static method in the subclass with the same signature as the one in the superclass, thus hiding it.
c. A subclass inherits all of its parent’s public and protected members, no matter what package the subclass is in.
d. You cannot declare new methods in the subclass that are not in the superclass.

These are NPTEL Programming In Java Week 3 Assignment 3 Answers

Q3. Consider the following piece of code.
Fill in the blank with the appropriate keyword(s) from the list given below so that the program compiles successfully.

a. abstract
b. final
c. default
d. public

Q4. How many instances of abstract class can be created?
a. 0
b. 1
c. 2
d. Multiple

These are NPTEL Programming In Java Week 3 Assignment 3 Answers

Q5. Structuring a Java class such that only methods within the class can access its instance variables is referred to as ______.
a. object orientation
b. inheritance
c. platform independence
d. encapsulation

Q6. Which of the following statement(s) is/are true?
a. A final method cannot be overridden in a subclass.
b. The advantage of private static methods is that they can be reused later if you need to reinitialize the class variable.
c. Class methods cannot use this keyword as there is no instance for this to refer to.
d. A final method can be overridden in a subclass.

These are NPTEL Programming In Java Week 3 Assignment 3 Answers

Q7. Consider the following piece of code.
Which of the following is the output of the above program?
a. Java
b. There will be a compile-time error.
c. JavaJava.
d. The program will give a runtime error.

Answer: b. There will be a compile-time error.

Q9. Consider the following program.
What is the output of the above program?
a. java
b. ring
c. r min
d. gram

These are NPTEL Programming In Java Week 3 Assignment 3 Answers

Q9. Which of the following statement(s) is/are False?
a. Hiding internal data from the outside world and accessing it only through publicly exposed methods is known as data encapsulation.
b. Common behavior can be defined in a superclass and inherited into a subclass using the extends keyword.
c. The term “class variable” is another name for a non-static field.
d. A local variable stores a temporary state; it is declared inside a method.

Answer: c. The term “class variable” is another name for a non-static field.

Q10. Which of the following statement(s) is/are true?
a. Static methods in interfaces are never inherited.
b. You will get a compile-time error if you attempt to change an instance method in the superclass to a static method in the subclass.
c. You can prevent a class from being subclassed by using the final keyword in the class’s declaration.
d. An abstract class can only be subclassed; it cannot be instantiated.

These are NPTEL Programming In Java Week 3 Assignment 3 Answers

### Programming In Java Programming Assignment Solution

Question 1

Define a class Point with two fields x and y each of type double. Also, define a method distance(Point p1, Point p2) to calculate the distance between points p1 and p2 and return the value in double.
Complete the code segment given below. Use Math.sqrt( ) to calculate the square root.

Solution:

``````class Point{
double x;
double y;

public static void distance(Point p1,Point p2){
double d;
d=Math.sqrt((p2.x-p1.x)*(p2.x-p1.x) + (p2.y-p1.y)*(p2.y-p1.y));
System.out.println(d);
}
}``````

These are NPTEL Programming In Java Week 3 Assignment 3 Answers

Question 2

This program to exercise the call of static and non-static methods. A partial code is given defining two methods, namely sum( ) and multiply ( ). You have to call these methods to find the sum and product of two numbers. Complete the code segment as instructed.

Solution:

``````QuestionScope st = new QuestionScope(); // Create an object to call non-
//static method
int result1=st.sum(n1,n2); // Call the method
int result2=QuestionScope.multiply(n1,n2);	// Create an object to call
//static method

System.out.println(result1);
System.out.println(result2);``````

These are NPTEL Programming In Java Week 3 Assignment 3 Answers

Question 3

Complete the code segment to swap two numbers using call by object reference.

Solution:

``````public static void swap(Question t) {
int temp = t.e1;
t.e1 = t.e2;
t.e2 = temp;
}``````

These are NPTEL Programming In Java Week 3 Assignment 3 Answers

Question 4

This program is related to the generation of Fibonacci numbers.>
For example: 0,1, 1,2, 3,5, 8, 13,… is a Fibonacci sequence where 13 is the 8th Fibonacci number.
A partial code is given and you have to complete the code as per the instruction given .

Solution:

``````if (n==1)      //Terminal condition
return 0;
else if(n==2)
return 1;
return fib(n - 1) + fib(n - 2); //Recursive call of function``````

These are NPTEL Programming In Java Week 3 Assignment 3 Answers

Question 5

A class Shape is defined with two overloading constructors in it. Another class Test1 is partially defined which inherits the class Shape. The class Test1 should include two overloading constructors as appropriate for some object instantiation shown in main() method. You should define the constructors using the super class constructors. Also, override the method calculate( ) in Test1 to calculate the volume of a Shape.

Solution:

``````//Template code:
double height;
Test1(double length,double h) {
//base class constructor with one parameter is called
super(length);
height=h;
}

//base class constructor having two argument is called
height=h;
}

double calculate()	{
}``````

These are NPTEL Programming In Java Week 3 Assignment 3 Answers

More Nptel courses: https://progiez.com/nptel/

Session: JULY-DEC 2022

Course Name: Programming in Java NPTEL

#### These are NPTEL Programming In Java Week 3 Assignment 3 Answers

Q1. Which of this keyword can be used in a sub class to call the constructor of super class?
a. super
b. this
c. extent
d. extends

Q2. What is the output of the above program?
a. i+jis 42 4
b. i+jis6 9 2
c. i+jis 42 9 2
d. i+jis 6 4

Q3. What is the output of the above program?
a. 4
b. 10
c. 2
d. runtime error

These are NPTEL Programming In Java Week 3 Assignment 3 Answers

Q4. For each description on the left, find the best matching modifier on the right. You may use a choice more than once or not at all.
1. Hides the instance variable from code in other files. A. private
2. Hides the method from code in other files B. public
3. Hides the subclass from code in other files. C. final
4. Exposes the API method to code in other files. D. static
5. Prevents the value of the instance variable from being Changed once initialized. E. none of the above

a. 1-A.2-A.3-C.4-D5-E
b. 1-A.2-A,3-A,4-B,5-C
c. 1-C.2-B.3-A, 4-A,5-D
d. None of Above

Q5. All the variables of interface should be?
a) default and final
b) default and static
c) public, static and final
d) protect, static and final

Answer: c) public, static and final

Q6. Which of the following statement(s) is/are NOT true?
a. A final method cannot be overridden in a subclass.
b. The advantage of private static methods is that they can be reused later if you need to reinitialize the class variable.
c. Class methods cannot use this keyword as there is no instance for this to refer to.
d. A final method can be overidden in a subclass.

Answer: d. A final method can be overidden in a subclass.

These are NPTEL Programming In Java Week 3 Assignment 3 Answers

Q7. Which of the following statements is/ are true?
a. Hello
b. There will be a compile-time error
c. HelloHello.
d. The program will give a runtime error.

Answer: d. The program will give a runtime error.

Q8. Which of the following option is true about the above program?
a. Eror: String cannot be a method return tpe like void, int, char, etc.; as it isa class.
b. Eror: Non-static variable ‘answer’ cannot be referenced from a static context.
c. Output: The answer to the question, Which course have you opted? is Programming with Java
d. Error: Compilation error as variable question’ is not static.

Answer: c. Output: The answer to the question, Which course have you opted? is Programming with Java

Q9. Disadvantage(s) of inheritance in Java programming is/are

b. two classes (base and inherited class) get tightly coupled
c. Save development time and effort
d. Code reusability

Answer: b. two classes (base and inherited class) get tightly coupled

These are NPTEL Programming In Java Week 3 Assignment 3 Answers

Q10. Which inheritance in Java programming is not supported?
a. Multiple inheritance using classes.
b. Multiple inheritance using interfaces.
c. Multilevel inheritance.
d. Single inheritance.

Answer: a. Multiple inheritance using classes.

These are NPTEL Programming In Java Week 3 Assignment 3 Answers

## Programming Assignment Solutions

Question 1

This program is related to the generation of Fibonacci numbers. For example: 0,1, 1,2, 3,5, 8, 13,… is a Fibonacci sequence where 13 is the 8th Fibonacci number. A partial code is given and you have to complete the code as per the instruction given below.

Solution:

``Code``

These are NPTEL Programming In Java Week 3 Assignment 3 Answers

Question 2

Define a class Point with two fields x and y each of type double. Also, define a method distance(Point p1, Point p2) to calculate the distance between points p1 and p2 and return the value in double.

Solution:

``Code``

These are NPTEL Programming In Java Week 3 Assignment 3 Answers

Question 3

A class Shape is defined with two overloading constructors in it. Another class Test1 is partially defined which inherits the class Shape. The class Test1 should include two overloading constructors as appropriate for some object instantiation shown in main() method. You should define the constructors using the super class constructors. Also, override the method calculate( ) in Test1 to calculate the volume of a Shape.

Solution:

``Code``

These are NPTEL Programming In Java Week 3 Assignment 3 Answers

Question 4

This program to exercise the call of static and non-static methods. A partial code is given defining two methods, namely sum( ) and multiply ( ). You have to call these methods to find the sum and product of two numbers. Complete the code segment as instructed.

Solution:

``Code``

These are NPTEL Programming In Java Week 3 Assignment 3 Answers

Question 5

Complete the code segment to swap two numbers using call by object reference.

Solution:

``Code``

These are NPTEL Programming In Java Week 3 Assignment 3 Answers

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