**UNIVERSITY EXAMINATIONS: 2018/2019**

**EXAMINATION FOR THE DEGREE OF BACHELOR OF SCIENCE IN**

**INFORMATION TECHNOLOGY/BUSINESS INFORMATION **

**TECHNOLOGY/APPLIED COMPUTING**

**BIT2204A JAVA PROGRAMMING**

**FULL TIME/PART TIME/DISTANCE LEARNING**

**DATE: APRIL, 2019 TIME: 2 HOURS**

**INSTRUCTIONS: Answer Question One & ANY OTHER TWO questions.**

**QUESTION ONE**

a) State and explain three types of scope qualifiers that are used in java programming

(3 Marks)

b) Describe the characteristics of the following methods and write a sample java for each

case (4 Marks)

i. Non- static method

ii. Static method

iii. Getter method

iv. Modifier method

c) Describe the difference between Do-while loop and while loop. Write a sample code

for each case (4 Marks).

d) Write a Java class that implements the following algorithm (5 Marks)

e) Briefly describe the meaning of the following concepts as used in Java programming

1. Start

2. Input/read Deposit amount

3. Input/read Years

4. Input/read Rate

5. Interest=Amount*Years*Rate/100

6. Print Interest

7. Stop

(3 Marks)

i. Interface

ii. Abstract class

iii. adapter class

f) Describe the difference between continue and break statement (2 Marks)

g) Write a Java class that calculate the area and circumference of a circle. The class

should have at least two methods (6 Marks)

h) Write a Java class that calculate the sum and the product of two numbers. 3 Marks)

**QUESTION TWO**

a) Write a Java class that use at least two methods to calculate and prints the area and

perimeter of a rectangle (6 Marks)

b) Write a Java class that swaps values of two variables (4 Marks)

c) The Euclidean algorithm is based on the principle that the greatest common divisor of

two numbers does not change if the larger number is replaced by its difference with

the smaller number. For example, 21 is the GCD of 252 and 105 (as 252 = 21 × 12

and 105 = 21 × 5), and the same number 21 is also the GCD of 105 and 252 − 105 =

147. Since this replacement reduces the larger of the two numbers, repeating this

process gives successively smaller pairs of numbers until the two numbers become

equal. When that occurs, they are the GCD of the original two numbers. By reversing

the steps, the GCD can be expressed as a sum of the two original numbers each

multiplied by a positive or negative integer, e.g., 21 = 5 × 105 + (−2) × 252. The fact

that the GCD can always be expressed in this way is known as Bézout’s identity.”

Write a Java program to prove that Euclid’s algorithm computes the greatest common

divisor of two positive given integers (10 Marks)

**QUESTION THREE**

a) Write a Java class that compare values of two variables and print the results.

(5 Marks)

b) Write a java program that implements the following flow chart (5 Marks)

c) Suppose you create an interface that defines relationships between two objects

according to the “natural order” of the objects as follows:

public interface Relation {

public boolean isGreater(Object a, Object b);

public boolean isLess( Object a, Object b);

public boolean isEqual( Object a, Object b); }

Create a class that implement the above interface and its methods. (10 Marks)

**QUESTION FOUR**

a) Write a Java program to create a two-dimension array (m x m) A[][] such that A[i][j]

is true if I and j are prime and have no common factors, otherwise A[i][j] becomes

false. (8 Marks)

b) Given the following superclass

public class Person

{ public String getName(){

System.out.println(

“Parent:

getName”); return

name;

}

}

write a code to override, the getName method in the subclass Student (6 Marks)

c) using an appropriate example of a program explain how method overloading is used to

facilitate polymorphism (6 Marks)

**QUESTION FIVE**

a) Write a Java method to find all twin prime numbers less than 100 (5 Marks)

b) Write a Java program to sort an array of positive integers of a given array, in the sorted

array the value of the first element should be maximum, second value should be

minimum value, third should be second maximum, fourth second be second minimum

and so on. (5 Marks)

c) Write a Java program which accepts students name, id, and Marks and display the

highest score and the lowest score. (5 Marks)

d) Write a Java program that accepts six numbers as input and sorts them in descending order.

(5 Marks)