Circle_Menu_driven_function

import java.util.Scanner;
public class Circle_Menu_driven_function
{
public static void main(String args[])
{
Scanner scanner = new Scanner(System.in);
double sum,d;
double div,pd;
System.out.println("enter radius");
int a =scanner.nextInt();
System.out.println("what you want to calculate \n1 diameter \n2 area \n3 circumference \n4 exit ");
int abs=scanner.nextInt();
if(abs==1)
{sum =(2*a);
System.out.println(+sum);
}
else if(abs==2)
{d=(3.14*a*a);
System.out.println(+d);
}
else if(abs==3)
{
pd=(3.14*a*2);
System.out.println(+pd);
}
else if(abs==4)
System.out.close();
else
System.out.println("choose right option");
}
}