Question

我有一个作业，我必须显示一个类的所有属性。

我的问题是如何在不必为person对象添加额外属性的情况下使代码工作？

我让代码工作但显然我不应该对原来的 person 类进行任何更改。这是：

class person
{
String firstName;
String lastName;
int age;

person(String informedFirstName, String informedLastName, int informedAge)
{
    firstName = informedFirstName;
    lastName = informedLastName;
    age = informedAge;
}

String whatIsUp()
{
 return "undetermined";
}
String getName()
{
    return firstName +" "+lastName;
}
String getAge()
{
    String str = String.valueOf(age);
    return str;
}

String getInfo()
{
    return ("Name = "+ getName() + " age="+ getAge());
}
}

我的工作代码是：

app class

class app

{
  public static void main(String[] args)
 {
student st1 = new student("Zack","Mills",21,".....");
professor p1 = new professor("Fred","Fonseca",44,".....");
TA ta1 = new TA("Paris","Hilton",20,"......");
System.out.println(st1.getInfo());
System.out.println(p1.getInfo());
System.out.println(ta1.getInfo());
 }
}

人类：

class person
{
String firstName;
String lastName;
int age;
    String status;

person(String informedFirstName, String informedLastName, 
int informedAge, String informedStatus) //< ---- added attribute informedStatus
{
    firstName = informedFirstName;
    lastName = informedLastName;
    age = informedAge;
            status = informedStatus;
}

String whatIsUp()
{
 return "undetermined";
}
String getName()
{
    return firstName +" "+lastName;
}
String getAge()
{
    String str = String.valueOf(age);
    return str;
}
    String getStatus(){
        return status;
    }

String getInfo()
{
    return ("Name = "+ getName() + " age="+ getAge()) + getStatus();
}

}

学生班：

class student extends person
{
String status;
student(String informedFirstName, String informedLastName, int informedAge, String informedStatus)
{
    super(informedFirstName, informedLastName, informedAge, informedStatus);
    if (age <= 25) status = informedStatus = "Traditional";
    else status = informedStatus = "Non-Traditional";
}

String whatIsUp()
{
 int n = 0;
 String b = "..."; 
 n = (int) (Math.random()*2);
 if (n == 0) b = "reading";
 if (n == 1) b = "talking";  
 return b;
}
String getStatus()
{
    return " Status = " + status;
}
}

教授班：

class professor extends person
{
String status;
professor(String informedFirstName, String informedLastName, int informedAge, String informedStatus)
{
    super(informedFirstName, informedLastName, informedAge, informedStatus);
    status = informedStatus = "Computer Science";
}

String whatIsUp()
{
 int n = 0;
 String b = "..."; 
 n = (int) (Math.random()*2);
 if (n == 0) b = "reading";
 if (n == 1) b = "talking";  
 return b;
}
String getStatus()
{
    return " Degree = " + status;
}
}

TA课程：

class TA extends person
{
String status;
TA (String informedFirstName, String informedLastName, int informedAge, String informedStatus)
{
    super(informedFirstName, informedLastName, informedAge, informedStatus);
    status = informedStatus = "Excellent";
}

String whatIsUp()
{
 int n = 0;
 String b = "..."; 
 n = (int) (Math.random()*2);
 if (n == 0) b = "reading";
 if (n == 1) b = "talking";  
 return b;
}
String getStatus()
{
    return " Communication Skills = " + status;
}
 }

对不起所有代码，非常感谢任何帮助。

Answer 1

我不确定在为person类添加一个属性时会出现什么问题。但是，如果您不想触摸它，我会建议您另类。

创建一个扩展人的类扩展。将新状态属性添加到该类。现在为TA，学生和教授扩展新的personExtension类。

class personExtension extends person
{
    String status;

personExtension(String informedFirstName, String informedLastName, int informedAge, String informedStatus)
{
    super(informedFirstName,informedLastName,informedAge);
    status = informedStatus;
}
}

Answer 2

实际上，您可以通过从studen扩展person并在新类中使用新属性status来完成所有操作。这样做你就拥有一个具有person所有属性的类，包括添加的新属性。

只需从人员中删除属性status，然后根据需要保持不变。

在student的构造函数中，使用person关键字传递super的属性。

student(String informedFirstName, String informedLastName, int informedAge,
        String informedStatus)
{
    super(informedFirstName, informedLastName, informedAge);
    if (age <= 25) status = informedStatus = "Traditional";
    else status = informedStatus = "Non-Traditional";
}

班级student的对象可让您访问所有属性

student s = new student("John", "Doe", 25, "some status");

只需添加一个，请尝试尊重java命名约定，类名应以大写字母开头。

修改

要让getInfo()返回包含状态的字符串，您必须在子类student中覆盖该方法，然后再次使用super关键字调用getInfo()来自{ {1}}并将person连接到它。

status

Java hw help：超类和属性

2 个答案: