showInputDialog 和 showMessageDialog的简单应用~

import javax.swing.*;
import java.lang.Math;
class Transfer{
public static void main(String args[]){
String xx,yy;
double x=0.0,y=0.0,trsx,trsy;
xx = JOptionPane.showInputDialog(null,"x的坐标值：");
x = Double.parseDouble(xx);
yy = JOptionPane.showInputDialog(null,"y的坐标值：");
y = Double.parseDouble(yy);
trsx = Math.sqrt(x*x+y*y);
trsy = Math.atan(y/x);
JOptionPane.showMessageDialog(null,"极径r： " + trsx +
"/n极角a: " +trsy,"结果",
JOptionPane.PLAIN_MESSAGE);
}
}