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.
Fill in the blanks:
The _________ refers to the current object.
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()?
If the name of the class is "Yellow", what can be the possible name for its constructors?
- yellow
- YELLOW
- Yell
- Yellow