Я пытаюсь написать класс Student, который должен работать с StudentDriver. Тем не менее, мне очень тяжело обволакивать концепцию методов и классов. Я не знаю, как получать и возвращать данные. Более того, я даже не знаю, правильно ли объявляю свои данные. Пожалуйста, помогите мне. Буду весьма признателен за это.Создание методов и классов (Java)
Также, когда я скомпилировал Студента, он говорит, что он не может найти символ this.setGPA. Как так? Когда в драйвере есть .setGPA.
спасибо.
// This will be the "driver" class for the Student class created in
// MinilabWritingClasses (It looks very complicated because of all
// the comments, but it really just creates instances of Student and
// tells them to do things...)
public class StudentDriver
{
public static void main(String[ ] args)
{
//create an instance of Student
System.out.println("***** Creating a Student, calling the default constructor");
Student stud1 = new Student();
//print it so we can see what the default values were for the class data
//note that its toString() will be called automatically
System.out.println("\n***** printing it - notice the default values (set by Java)");
System.out.println(stud1);
//create another instance of a Student, passing in initial values to its constructor
System.out.println("\n***** Creating another Student, passing initial values to its constructor");
Student msBoss = new Student("Bill Gates", 56, 'm', 3.2, true);
//tell it to return its age
System.out.println("\n***** telling it to return its age.");
int theAge = msBoss.getAge();
System.out.println("Its age is: " + theAge);
//print it - note that its toString() will be called automatically;
System.out.println("\n***** printing it - see if values are correct");
System.out.println(msBoss);
//ask it if it is on probation
System.out.println("\n***** asking it if it is on probation (check answer)");
System.out.println("onProbation() returned: " + msBoss.onProbation());
//tell it to change its gpa to 1.3
System.out.println("\n***** telling it to change its gpa to 1.3");
msBoss.setGPA(1.3);
//print it now
System.out.println("\n***** printing it - see if the values are correct");
System.out.println(msBoss);
//ask it if it is on probation now
System.out.println("\n***** asking it if it is on probation (check answer)");
boolean boolAnswer = msBoss.onProbation();
System.out.println("onProbation() returned: " + boolAnswer);
//tell it to complain
System.out.println("\n***** telling it to complain");
System.out.println("complain() returned: " + msBoss.complain());
//tell it to change its onScholarship field to false
System.out.println("\n***** telling it to change its onScholarship field to false");
msBoss.setOnScholarship(false);
//print it now
System.out.println("\n***** printing it - see if the values are correct");
System.out.println(msBoss);
//ask it if it is on probation now
System.out.println("\n***** asking it if it is on probation (check answer)");
boolAnswer = msBoss.onProbation();
System.out.println("onProbation() returned: " + boolAnswer);
//create a different student, tell it to have some different values, and tell it to print itself
System.out.println("\n***** creating a different Student, passing initial values to its constructor");
Student stud2;
stud2 = new Student("Hillary Clinton", 64, 'f', 2.0, true); //notice-can define variable and create it in 2 steps
//print it
System.out.println("\n***** printing it - see if the values are correct");
System.out.println(stud2);
//ask it if it is on probation now
System.out.println("\n***** asking it if it is on probation (check answer)");
boolAnswer = stud2.onProbation();
System.out.println("onProbation() returned: " + boolAnswer);
}
}
Вот класс, который я пишу.
public class Student
{
private String name;
private int age;
private char gender;
private double gpa;
private boolean onScholarship;
public Student()
{
}
public Student(String newName, int newAge, char newGender, double newGPA, boolean newScholarship)
{
this.name = newName;
this.age = newAge;
this.gender = newGender;
this.gpa = newGPA;
this.onScholarship = newScholarship;
}
public int getAge(int newAge)
{
return age;
}
public double setGPA (double newGPA)
{
this.setGPA = newGPA;
}
public boolean setOnScholarship (boolean newScholarship)
{
this.setOnScholarship = newScholarship;
}
public String toString()
{
return this.name + "\t" + this.age + "\t" + this.gender + "\t" + this.setGPA + "\t" + this.setOnScholarship;
}
public boolean onProbation()
{
if (onScholarship==true && gpa < 2.0)
return true;
else
return false;
}
}
Что такое '' определенные данные'? Можете быть более конкретными? – sam
В значительной степени я имею в виду все из них, boolean, int, string, double, char и т. Д. – Paincakes
Это должно быть 'this.gpa'. Кроме того, поскольку вы не возвращаетесь из 'setter', сделайте его' void' – sam