java - 根据用户输入查找输入形状的面积

Question

我想用 Java 创建一个程序，它根据用户输入查找输入形状的面积。但我没能实现这一目标。

这是我的脚本:

import java.util.Scanner;

public class area {
static Scanner advance = new Scanner(System.in);
public  void main(String[] args) {

    nu();
}
int length;
    int height;
int area;


public  void nu(){
    String message = advance.nextLine();

    if (message.equalsIgnoreCase("rectangle")){

        System.out.println("Enter the length of the rectangle: ");

        length  = advance.nextInt();

        //length declared.//
        System.out.println("Enter the height of the rectangle");

        height = advance.nextInt();

        //Height has been declared.//

        area = length * height;

        System.out.print("The area is: " + area);
    }
}
}

第一个问题是，这段代码没有运行，所以我不知道它是否有效。其他一切都很好。你能告诉我，我做错了什么吗？

Answer 1

您需要将static添加到main方法中，并创建一个area的新实例。请参阅下面的代码。

public class area {
static Scanner advance = new Scanner(System.in);
public static void main(String[] args) {

    new area().nu();
}
int length;
int height;
int area;


public  void nu(){
    String message = advance.nextLine();

    if (message.equalsIgnoreCase("rectangle")){

        System.out.println("Enter the length of the rectangle: ");

        length  = advance.nextInt();

        //length declared.//
        System.out.println("Enter the height of the rectangle");

        height = advance.nextInt();

        //Height has been declared.//

        area = length * height;

        System.out.print("The area is: " + area);
    }
  }
}