Java：基本类定义

Java: Basic class definition

提问by Java123

Define the missing method. licenseNum is created as: (100000 * customID) + licenseYear. Sample output: Dog license: 77702014

定义缺失的方法。licenseNum 被创建为：(100000 * customID) + licenseYear。样本输出：狗牌：77702014

This is what I did:

这就是我所做的：

 public void createLicenseNum() {
    licenseNum = (licenseNum * 100000) + licenseYear;
    return;
 }

But it's incorrect. Where am I going wrong?

但这是不正确的。我哪里错了？

CallDogLicense. java:32: createLicenseNum() in DogLicense cannot be applied to (int) dog1.createLicenseNum(777);

呼叫狗执照。java:32：DogLicense 中的 createLicenseNum() 不能应用于 (int) dog1.createLicenseNum(777)；

Code from file DogLicense.java

来自文件 DogLicense.java 的代码

    public class DogLicense {
      private int licenseYear;
      private int licenseNum;

      public void setYear(int yearRegistered) {
        licenseYear = yearRegistered;
        return;
      }

      // FIXME: Write createLicenseNum()

      /* Your solution goes here  */

      public void createLicenseNum() {
        licenseNum = (licenseNum * 100000) + licenseYear;
        return;
      }

      public int getLicenseNum() {
        return licenseNum;
      }
    }

Code from file CallDogLicense.java

来自文件 CallDogLicense.java 的代码

    public class CallDogLicense {
      public static void main (String [] args) {
        DogLicense dog1 = new DogLicense();

        dog1.setYear(2014);
        dog1.createLicenseNum(777);
        System.out.println("Dog license: " + dog1.getLicenseNum());

        return;
      }
    }

回答by Robby Cornelissen

You need to add the customIDargument to your method and use it in your calculation:

您需要将customID参数添加到您的方法中并在您的计算中使用它：

public void createLicenseNum(int customID) {
    licenseNum = (customID * 100000) + licenseYear;
}

回答by Shadov

Your method doesn't have any arguments, it's not javascript. You need to do this:

您的方法没有任何参数，它不是 javascript。你需要这样做：

public void createLicenseNum(int customId) {...

public void createLicenseNum(int customId) {...

Now if you call it like this dog.createLicenseNum(500);then inside that method variable named customIdwill have a value 500.

现在，如果您像这样调用它，dog.createLicenseNum(500);那么在名为的方法变量customId中将有一个 value 500。

回答by xenteros

Your're calling the method with int, however it's declared to take no parameters.

您正在使用 调用该方法int，但它被声明为不带参数。

public void createLicenseNum(int licenseNum) {
  this.licenseNum = (licenseNum * 100000) + licenseYear;
return;

Will solve the problem.

会解决问题。

Still it's not how we do that in Java. For constructing objects you should use constructor.

这仍然不是我们在 Java 中这样做的方式。对于构造对象，您应该使用构造函数。

public class DogLicense {
    private int licenseYear;
    private int licenseNum;

    public void setYear(int yearRegistered) {
      licenseYear = yearRegistered;
      return;
    }


    public DogLicense(int num, int year) {
        licenseNum = (num* 100000) + year;
    }

    public int getLicenseNum() {
        return licenseNum;
    }
}

public class CallDogLicense {
    public static void main (String [] args) {
      DogLicense dog1 = new DogLicense(777, 2014);
      System.out.println("Dog license: " + dog1.getLicenseNum());
      return;
  }
}