Computer Applications
Consider the following Java class and answer the questions given below:
class Rectangle
{
int length, breadth;
Rectangle()
{
length = 5;
breadth = 3;
}
Rectangle(int l, int b)
{
length = l;
breadth = b;
}
void area()
{
System.out.println("Area: " + (length * breadth));
}
public static void main(String args[])
{
Rectangle r1 = new Rectangle();
Rectangle r2 = new Rectangle(8, 4);
r1.area();
r2.area();
}
}
(a) Name the type of constructors used in the above class.
(b) What is the output of the method main()?
Answer
(a) Default constructor & Parameterized constructor
(b) Output
Area: 15
Area: 32
Reason
The types of constructors used in the given program are:
1. Default Constructor:
Rectangle()
{
length = 5;
breadth = 3;
}
- A default constructor is a constructor that does not take any parameters.
- It initializes
length = 5
andbreadth = 3
.
2. Parameterized Constructor:
Rectangle(int l, int b)
{
length = l;
breadth = b;
}
- A parameterized constructor is a constructor that takes arguments (
int l
andint b
in this case). - It allows for initializing the instance variables
length
andbreadth
with specific values provided during object creation.
Output of the program
Rectangle r1 = new Rectangle();
Calls the default constructorRectangle()
→length = 5
andbreadth = 3
Rectangle r2 = new Rectangle(8, 4);
Calls the parameterized constructorRectangle(int l, int b)
→length = 8
andbreadth = 4
r1.area();
Prints value of Area →5 x 3
=15
r2.area();
Prints value of Area →8 x 4
=32
Related Questions
Define a class named FruitJuice with the following description:
Data Members Purpose int product_code stores the product code number String flavour stores the flavour of the juice (e.g., orange, apple, etc.) String pack_type stores the type of packaging (e.g., tera-pack, PET bottle, etc.) int pack_size stores package size (e.g., 200 mL, 400 mL, etc.) int product_price stores the price of the product Member Methods Purpose FruitJuice() constructor to initialize integer data members to 0 and string data members to "" void input() to input and store the product code, flavour, pack type, pack size and product price void discount() to reduce the product price by 10 void display() to display the product code, flavour, pack type, pack size and product price Fill in the blanks:
A constructor has return _________ type.
Fill in the blanks to design a class:
class __________{
int l, b;
Area(int __________, int __________) {
l = __________;
b = __________;
}
}What is meant by a constructor?