Program to Find the Area of a Circle in Java.

There are following way to find the Area of a Circle in Java.

Using area of a circle:-

• First take input value of radius in float.
• Calculate the area of circle using formula (3.14 * radius * radius)
• Print the area of circle.

Using DoubleStream function:-

• DoubleStream of(double) return a sequential double elements.
• Inside map() function Calculate the area of circle using formula (3.14 * radius * radius)and return a DoubleStream.
• Through forEach() loop to print area of circle.

import java.util.stream.DoubleStream;

public class AreaOfCircle {
	public static void main(String[] args) {
		
		double radius = 1.5;
		double area = 3.14 * radius * radius;
		System.out.println("area of circle is :- " + area);
		
		System.out.println("Using java 8 to find area of circle  :- ");
		DoubleStream.of(radius).map(a -> a * a * 3.14).forEach(System.out::println);
	}
}

Output :-
area of circle is :- 7.0649999999999995
Using java 8 to find area of circle :-
7.065