//InputDialog.java
//demo of input (and output) with JOptionPane windows

import javax.swing.*;     //needed for JOptionPane

public class InputDialog {
    public static void main (String [] args) {

	String name, input;   
	int age;              
	double radius, circumference, area;

	//JOptionPane input dialog window.
	//showInputDialog method has prompt string parameter,
	//  returns a String, assign it to a string variable:
	name = JOptionPane.showInputDialog( "Enter your name please" );

	//showMessageDialog displays a string
	JOptionPane.showMessageDialog( null, "Welcome: " + name );
	//null must be the first argument.
	//2nd argument is string, here concatenation.


	//***********************************************
	input = JOptionPane.showInputDialog( "Enter your age in years" );
	//to input an int, need to convert String to int:
	age = Integer.parseInt( input );   //extremely finicky!
	//parameter to parseInt is a string.  
	//returns an int value, assign it to int variable.
	
	age = age + 1;   
	JOptionPane.showMessageDialog( null, "Next birthday you will be: " + 
				              age );


	//***********************************************
	input = JOptionPane.showInputDialog( "Enter radius of a circle" );
	//to input a double, need to convert String to double:
	radius = Double.parseDouble( input );  //very finicky!
	//parameter to parseDouble is a string.  
	//returns a double value, assign it to double variable.
	
	circumference = 2 * Math.PI * radius;
	area = Math.PI * radius*radius;

	JOptionPane.showMessageDialog( null, "Circumference=" + circumference +
				             "\nArea=" + area);
    }
}