squareapplet.java

java小程序

import java.awt.Graphics;
import javax.swing.*;
public class SquareApplet extends JApplet
{
double n,s;
public void init()
{
String nStr=JOptionPane.showInputDialog("输入一个浮点数：");
n=Double.parseDouble(nStr);
s=n*n;
}
public void paint(Graphics g)
{
g.drawRect(40,30,150,55);
g.drawString(n+"的平方："+s,50,50);
}
}