JAVA学习笔记-基本输入输出示例

package javaapplication1;

import javax.swing.JOptionPane;
import java.util.Scanner;

public class JavaApplication1 {
    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);
        System.out.print("Please input a double:");
        
        double radius = input.nextDouble();
        double area = 3.1415 * radius * radius;
        
        System.out.println("Area is :" + area);
    }  
}