Question

嘿那里，我被卡住了。我已经在代码中遇到了2个问题，但我对如何解决问题感到茫然。作业大多是胡说八道：

import java.util.*;

class Business {
    private String name, phone;
    private int employees, age;

    void Business(){
        name = "Foo Inc.";
        phone = "";
        employees = 0;
        age = 0;

        System.out.println("In default constructor!");
        printVals();
    }

    void Business(String name, String phone, int employees){ 
        System.out.printf("%s %s %d\n", name, phone, employees);

        this.name = name;
        this.phone = phone;
        this.employees = employees;
        this.age = 0;

        System.out.println("In constructor!");
        printVals();
    }

    void printVals(){
        System.out.printf("name: %s\n", name);
        System.out.printf("phone: %s\n", phone);
        System.out.printf("employees: %d\n", employees);
        System.out.printf("age: %d\n", age);
    }

    public static void main(String [] args)
    {
        Business[] mall = new Business[5];
        String[] names = {"The Gap",
                          "Savers",
                          "Academy of Salon Professionals",
                          "Ron's Farmhouse"};
        String[] phones = {"555-555-5555", "555-555-5556", 
                           "555-555-5557", "555-555-5558"};
        int[] emps = {20, 24, 75, 32};
        int i, num = 4;


        mall[num - 1] = new Business();
        for(i = 0; i < num; i++){
            mall[i] = new Business(names[i], phones[i], emps[i]);
            System.out.printf("init Business: %s %s %d\n", 
                    names[i], phones[i], emps[i]);
        }
    }
}

这是来自javac的输出错误：

Business.java:51: cannot find symbol
symbol  : constructor Business(java.lang.String,java.lang.String,int)
location: class Business
            mall[i] = new Business(names[i], phones[i], emps[i]);
                      ^
1 error

我不明白为什么它告诉我它找不到构造函数。据我所知，参数是相同的......

假设我注释掉了Business（）调用的参数，这样它只调用默认的构造函数。至少它编译的方式，但是，方法中的System.out.print *都不会打印任何东西！

任何帮助都将不胜感激。

Answer 1

您正在使用void Business定义构造函数。构造函数没有返回类型，因此只需在Business“构造函数”和new能够找到它们之前删除void。

/* remove void */ 
Business(String name, String phone, int employees){ 
    System.out.printf("%s %s %d\n", name, phone, employees);

    this.name = name;
    this.phone = phone;
    this.employees = employees;
    this.age = 0;

    System.out.println("In constructor!");
    printVals();
}

Answer 2

从构造函数中删除void

Java - 构造函数问题和方法内的System.out.print

2 个答案: