Question 1

Question 1Define objects. Give a real life example to explain objects along with their attributes and behaviour.

Accepted Answer

An object represents data (attributes) and its related methods (behaviour) as a single unit. Take the example of a car. When we describe a car as an object, there are a number of physical factors which contribute to define its state such as its brand name, colour, speed, size, number of seats, etc. In addition, the car has several functional definitions. It transports people to different locations by controlling its speed and direction, an accelerator to increase or decrease its speed and brakes to stop it. Thus we can say that car is an object that combines its attributes and behaviour as a single unit.

Question 2

Question 3What do you understand by the term Polymorphism?

Accepted Answer

The word Polymorphism means "many forms". Polymorphism helps the programmer to use the same function name for more than one purpose.

Question 3

Question 4What are operators? Why do we need them?

Accepted Answer

Operators are special symbols that are used to perform calculations. We need operators to form expressions by applying them to the variables and constants.

Question 4

Question 5What do you understand by the term Keyword?

Accepted Answer

Keywords are reserved words that have a special meaning for the Java compiler. Java compiler reserves these words for its own use so Keywords cannot be used as identifiers. For example, void, public, class, int, etc.

Question 5

Question 6What are variables? How are they different from Constants?

Accepted Answer

A variable is a named location in the memory which stores data temporarily. A variable has a unique name, a type and a size that is used to identify it in a program.Difference between variables and constants is that the value of variables can change during the execution of the program whereas value of constants are fixed and does not change during program execution.

Question 6

Question 2Kareena is writing a program in Java to calculate the average of three subjects. Which operators will she use for the same?

Accepted Answer

Kareena will use the addition operator (+) to first calculate the total marks obtained in all three subjects. After that, she will use the division operator (/) to divide the total marks by 3 to get the average.

Question 7

Question 7Write a program to calculate the tax for a taxable income of Rs. 4,10,000, if the tax rate is fixed at 3.2%.public class KboatTax
{
    public static void main(String args[]) {
        int income = 410000;
        double rate = 3.2;
        double tax = income * rate / 100;
        System.out.println("Tax = " + tax);
    }
}Output

Accepted Answer

Please refer to the full solution above.

Question 8

Question 8Create a program that will generate a bill at McDonald's for four vegetable burgers (@ Rs 45 per vegetable Burger) and three vegetable McPuffs (@ Rs 25 per vegetable McPuff). There is a special Independence Day discount of Rs 50 on the final bill amount.public class KboatMcDBill
{
    public static void main(String args[]) {
        int vegBurgerCost = 4 * 45;
        int vegMcPuffCost = 3 * 25;
        int total = vegBurgerCost + vegMcPuffCost;
        int amt = total - 50;
        System.out.println("4 Vegetable Burgers @ 45 = " + vegBurgerCost);
        System.out.println("3 Vegetable McPuffs @ 25 = " + vegMcPuffCost);
        System.out.println("Total = " + total);
        System.out.println("Discount = 50");
        System.out.println("Final Bill = " + amt);
    }
}Output

Accepted Answer

Please refer to the full solution above.

Introduction to Java & BlueJ

Answer the following

Application Based Questions

Lab Session