Lab Sheet 4: Expressions and Operators in Java

Task 1: Assignment and Arithmetic Operators

Exercise 1: Arithmetic Operations

Objective: Write and execute a Java program to compute arithmetic expressions.

Steps:

1. Create a Java class named ArithmeticOperations.

2. Declare variables a = 10, b = 5.

3. Compute and print the following:

   • a + b * 2

   • (a + b) * 2

   • a % b + 5

4. Compile and run the program.

Expected Output:

Result1: 20  
Result2: 30  
Result3: 5

Exercise 2: Increment and Decrement Operators

Objective: Experiment with increment (++) and decrement (--) operators.

Steps:

1. Create a Java class named IncrementDecrementDemo.

2. Initialize int x = 5.

3. Apply the following operations:

   • x += 3

   • x++

   • --x

4. Print the final value of x.

5. Compile and run the program.

Expected Output:

Final x: 8

Task 2: Relational and Logical Operators

Exercise 1: Relational Expressions

Objective: Write a program to test relational expressions.

Steps:

1. Create a Java class named RelationalOperatorsDemo.

2. Declare variables x = 3, y = 5.

3. Print the results of the following expressions:

   • x == 3

   • x >= y

   • y < 10

   • x - y <= 0

4. Compile and run the program.

Expected Output:

true  
false  
true  
true

Exercise 2: Logical Operators

Objective: Evaluate logical expressions with given values.

Steps:

1. Create a Java class named LogicalOperatorsDemo.

2. Initialize variables:

    int a = 5, b = 2, c = 4, d = 5;
   

3. Print the results of:

   • a == 5

   • b * d == c * c

   • d % b * c > 5 || c % b * d < 7

   • d % b * c > 5 && c % b * d < 7

4. Compile and run the program.

Expected Output:

true  
false  
true  
false

Task 3: Bitwise and Shift Operators

Exercise 1: Bitwise Operations

Objective: Perform bitwise operations and observe results.

Steps:

1. Create a Java class named BitwiseDemo.

2. Initialize int a = 60, int b = 13.

3. Compute and print:

   • a & b

   • a | b

   • a ^ b

   • ~a

   • a << 2

   • a >> 2

4. Compile and run the program.

Expected Output:

a & b = 12  
a | b = 61  
a ^ b = 49  
~a = -61  
a << 2 = 240  
a >> 2 = 15

Task 4: Practical Programming Problems

Exercise 1: Convert Meters to Kilometers and Meters

Objective: Write a program to convert a given distance in meters to kilometers and meters.

Steps:

1. Create a Java class named DistanceConverter.

2. Take input (e.g., 2500 meters).

3. Compute:

   • km = meters / 1000

   • remainingMeters = meters % 1000

4. Print the result.

5. Compile and run the program.

Expected Output (for input 2500):

2 km and 500 m

Exercise 2: Fahrenheit to Celsius Conversion

Objective: Convert Fahrenheit to Celsius using the formula.

Steps:

1. Create a Java class named TemperatureConverter.

2. Take input (e.g., 45°F).

3. Compute:

    celsius = (fahrenheit - 32) * 5.0 / 9;
   

4. Print the result rounded to 2 decimal places.

5. Test with 45°F and -87°F.

Expected Output:

45°F = 7.22°C  
-87°F = -66.11°C

Exercise 3: Extract Digits of a 3-Digit Number

Objective: Write a program to print individual digits of a 3-digit number.

Steps:

1. Create a Java class named DigitExtractor.

2. Take input (e.g., 456).

3. Compute:

   • digit1 = num / 100

   • digit2 = (num / 10) % 10

   • digit3 = num % 10

4. Print the digits.

5. Compile and run the program.

Expected Output (for input 456):

4, 5, 6

Exercise 4: Calculate the Area of a Circle

Objective: Compute the area of a circle using Math.PI.

Steps:

1. Create a Java class named CircleArea.

2. Take input for radius (e.g., 5.0).

3. Compute:

    area = Math.PI * radius * radius;
   

4. Print the result.

5. Compile and run the program.

Expected Output (for radius 5.0):

Area: 78.53981633974483