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
Fill in the blanks:
A _________ constructor creates objects by passing value to it.
Explain the following terms:
Copy constructor
If the name of the class is "Yellow", what can be the possible name for its constructors?
- yellow
- YELLOW
- Yell
- Yellow
Consider the given program and answer the questions given below:
class temp { int a; temp() { a=10; } temp(int z) { a=z; } void print() { System.out.println(a); } void main() { temp t = new temp(); temp x = new temp(30); t.print(); x.print(); } }
(a) What concept of OOPs is depicted in the above program with two constructors?
(b) What is the output of the method main()?