Java 编译器说找不到符号

编译器抛出一个异常，说明：

找不到符号p和x

该程序接受用户输入，并根据循环条件打印。编译时，它会抛出一个找不到符号的错误

import java.util.Scanner;
class Puppy{
    String name;
    String breed;
    String gender;
    int weight;
    int age;
    int loud;

    void hammer()
    {
        System.out.println("Enter your Dogs name :");
        p[x].name = user_input.next();
        System.out.println("Enter your Dogs Breed :");
        p[x].breed = user_input.next();
        System.out.println("Enter your Dogs Gender :");
        p[x].gender = user_input.next();
        System.out.println("Enter your Dogs weight in Kg:");
        p[x].weight = user_input.nextInt();
        System.out.println("Enter your Dogs age :");
        p[x].age = user_input.nextInt();
        System.out.println("Rate your Dogs Loudness out of 10 :");
        p[x].loud = user_input.nextInt();       
    }

    void jammer()
    {
        System.out.println("Hello my name is" + " " + p[x].name);
        System.out.println("I am a" + " " + p[x].breed);
        System.out.println("I am" + " " + p[x].age + " " + "years old" + " " + p[x].gender);
        System.out.println("I weigh around" + " " + p[x].weight + " " + "kg's");
        System.out.println("I sound this loud" + " " + p[x].loud);  
    }
}

class PuppyTestDrive
{
    public static void main(String []args)
    {
        Scanner user_input = new Scanner(System.in);
        int x = 0;
        Puppy[] p = new Puppy[4];

        while(x < 4)
        {
            p[x] = new Puppy();
            p[x].hammer();
            p[x].jammer();
            x = x + 1;
        }
    }
}

---

您的程序应使用以下代码：

import java.util.Scanner; 

class Puppy{

    String name;
    String breed;
    String gender;
    int weight;
    int age;
    int loud;

    void hammer()
    {
        Scanner user_input = new Scanner(System.in);
        System.out.println("Enter your Dogs name :");
        this.name = user_input.next();
        System.out.println("Enter your Dogs Breed :");
        this.breed = user_input.next();
        System.out.println("Enter your Dogs Gender :");
        this.gender = user_input.next();
        System.out.println("Enter your Dogs weight in Kg:");
        this.weight = user_input.nextInt();
        System.out.println("Enter your Dogs age :");
        this.age = user_input.nextInt();
        System.out.println("Rate your Dogs Loudness out of 10 :");
        this.loud = user_input.nextInt();       
    }

    void jammer()
    {
        System.out.println("Hello my name is" + " " + this.name);
        System.out.println("I am a" + " " + this.breed);
        System.out.println("I am" + " " + this.age + " " + "years old" + " " + this.gender);
        System.out.println("I weigh around" + " " + this.weight + " " + "kg's");
        System.out.println("I sound this loud" + " " + this.loud);  
    }
}

class PuppyTestDrive {

    public static void main(String []args)
    {                
        int x = 0;
        Puppy[] p = new Puppy[4];

        while(x < 4)
        {
            p[x] = new Puppy();
            p[x].hammer();
            p[x].jammer();
            x = x + 1;
        }
    }
}

---

您试图在函数hammer中使用变量“p”，但它在main方法中是堆栈变量。您需要将其作为类的属性。hammer和jammer方法不知道p和XY，您使用局部变量作为全局变量。您需要将P和X声明为全局变量，或者在hammer中声明为局部变量。提示：不要这样做：不要编写100行代码来运行编译器。只需写一些你认为应该编译的小部分。然后运行编译器。然后仔细阅读它的错误消息。Java编译器消息非常好，大多数情况下，它们准确地告诉您发生了什么。然后修复错误，再编写几行代码。提示：你的名字真的很糟糕。变量的名称应该告诉您变量是什么。p和x。。。什么也别说。方法的名称也一样。别开玩笑了。没有人喜欢写得不好的代码。只是一个细节：你可以用一些文本替换+一些文本+，甚至可以省略这个。。