Question

所以我在main类中有两个重载方法，我试图用来设置一个对象的值。这些方法来自另一个类，但它似乎没有做任何事情。当我使用显示方法时，它会打印出Customer的原始值，而不是该方法设置的新值。

public class Customer {
    int customerID = 0;
    String name = "Name required";
    String address = "Address required";
    String phoneNumber = "Phone Required";
    String eMail = "email optional";

    public void setCustomerInfo(int ID, String nm, String addr, String phn) {
        int customerID = ID;
        String name = nm;
        String address = addr;
        String phoneNumber = phn;
    }

    public void setCustomerInfo(int ID, String nm, String addr, String phn, String mail) {
        int customerID = ID;
        String name = nm;
        String address = addr;
        String phoneNumber = phn;
        String eMail = mail;
    }

    public void display() {
        System.out.println("Customer ID: " + customerID);
        System.out.println("Customer Name: " + name);
        System.out.println("Customer Address: " + address);
        System.out.println("Customer Phone Number: " + phoneNumber);
        System.out.println("Customer Email Address: " + eMail);
    }
}

-

public class CustomerTest {
    public static void main(String args[]) {
        Customer c1 = new Customer();
        Customer c2 = new Customer();

        c1.setCustomerInfo(1, "Greg", "123 Real Street", "1234-5678");
        c2.setCustomerInfo(2, "Mike", "123 Fake Street", "9876-5432", "RealEmails@Emails.com");

        System.out.println(c1.name);

        c1.display();
        c2.display();
    }
}

但程序会打印Customer实例的初始值：

Name required
Customer ID: 0
Customer Name: Name required
Customer Address: Address required
Customer Phone Number: Phone Required
Customer Email Address: email optional
Customer ID: 0
Customer Name: Name required
Customer Address: Address required
Customer Phone Number: Phone Required
Customer Email Address: email optional

Answer 1

您的方法是将值分配给局部变量而不是类成员。将它们更改为：

public void setCustomerInfo(int ID, String nm, String addr, String phn) {

    customerID = ID;
    name = nm;
    address = addr;
    phoneNumber = phn;
}

public void setCustomerInfo(int ID, String nm, String addr, String phn, String mail) {

    customerID = ID;
    name = nm;
    address = addr;
    phoneNumber = phn;
    eMail = mail;
}

重载方法不会更改对象中的值

1 个答案: