addtwodouble.java

用java实现的用户输入两个数相加

//import the nessary class 
import java.awt.Graphics;

import javax.swing.JApplet;
import javax.swing.JOptionPane;

public class AddTwoDouble extends JApplet{
	double sum;
	public void init (){
		String theNum1,theNum2;
        theNum1 = JOptionPane.showInputDialog(null,"The First Number");
	    theNum2 = JOptionPane.showInputDialog(null,"The Second Nubmber");
		
		double num1,num2;
		num1 = Double.parseDouble(theNum1);
		num2 = Double.parseDouble(theNum2);

		sum = num1 + num2;
    }
	
	public void paint (Graphics g){
		super.paint(g);
		g.drawString("the sum is =" + sum, 25,25);
	}
    
};