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()?
Java Constructors
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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 = 5andbreadth = 3.
2. Parameterized Constructor:
Rectangle(int l, int b)
{
length = l;
breadth = b;
}
- A parameterized constructor is a constructor that takes arguments (
int landint bin this case). - It allows for initializing the instance variables
lengthandbreadthwith specific values provided during object creation.
Output of the program
Rectangle r1 = new Rectangle();
Calls the default constructorRectangle()→length = 5andbreadth = 3Rectangle r2 = new Rectangle(8, 4);
Calls the parameterized constructorRectangle(int l, int b)→length = 8andbreadth = 4r1.area();
Prints value of Area →5 x 3=15r2.area();
Prints value of Area →8 x 4=32
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