Question

I am to complete the following for Java but getting compiler errors...Implement a base class called Student that contains a name and major. Implement the subclass GraduateStudent, which adds a property called stipend.

Here is what I have for code with the compiler error following.

public class GraduateStudent extends Student {
  
   private double stipend;
  
   public GraduateStudent(String name, String major, double stipend) {
      
       super(name);
       super(major);
  
       this.stipend = stipend;
      
   }
  
   public void setStipend(double stipend) {
       this.stipend = stipend;
   }
  
   public double getStipend() {
       return stipend;
   }
}

public class Student {
  
protected String name;
protected String major;
  
public Student(String name, String major) {
this.name = name;
this.major = major;
}
  
public void setName(String name) {
this.name = name;
}
  
public String getName() {
return name;
}
  
public void setMajor(String major) {
this.major = major;
}
  
public String getMajor() {
return major;
}
}

GraduateStudent.java:7: error: constructor Student in class Student cannot be applied to given types;
                super(name);
                ^
  required: String,String
  found: String
  reason: actual and formal argument lists differ in length
GraduateStudent.java:8: error: call to super must be first statement in constructor
                super(major);
                     ^
2 errors
[ERROR] did not compile; check the compiler stack trace field for more info

PROGRAM EXECUTION STACK TRACE

[ERROR] did not compile; check the compiler stack trace field for more info

YOUR CODE'S OUTPUT

1	[ERROR] did not compile; check the compiler stack trace field for more info
2
3	false

Answer 1

• Errors of the given program are solved in following solution.
• Comments are made wherever changes are made.
• Main class is used to create objects of class and to call methods.
• Program snippet is attached below the typed code.
• Sample output snippet is provided at the end.

Program:

class Student 
{
    protected String name;
    protected String major;

    public Student(String name, String major) 
    {
        this.name = name;
        this.major = major;
    }

    public void setName(String name) 
    {
        this.name = name;
    }

    public String getName() 
    {
        return name;
    }

    public void setMajor(String major) 
    {
        this.major = major;
    }

    public String getMajor() 
    {
        return major;
    }
}

class GraduateStudent extends Student 
{

    private double stipend;

    public GraduateStudent(String name, String major, double stipend) 
    {
        /* This is the part where you made mistake */
        /* Super class constructor should be called like this */
        super(name, major);
        this.stipend = stipend;
    }

    public void setStipend(double stipend) 
    {
        this.stipend = stipend;
    }

    public double getStipend() 
    {
        return stipend;
    }
}

/* Main class for creating object of GraduateStudent class to test the code*/
public class Main 
{
    public static void main(String[] args) 
    {
        GraduateStudent g = new GraduateStudent("John", "Computer", 1500);

        // calling GraduateStudent methods
        System.out.println(g.getName());
        System.out.println(g.getMajor());
        System.out.println(g.getStipend());
    }
}

Program Snippet:

class Student 
{
    protected String name;
    protected String major;

    public Student(String name, String major) 
    {
        this.name = name;
        this.major = major;
    }

    public void setName(String name) 
    {
        this.name = name;
    }

    public String getName() 
    {
        return name;
    }

    public void setMajor(String major) 
    {
        this.major = major;
    }

    public String getMajor() 
    {
        return major;
    }
}

class GraduateStudent extends Student 
{

    private double stipend;

    public GraduateStudent(String name, String major, double stipend) 
    {
        /* This is the part where you made mistake */
        /* Super class constructor should be called like this */
        super(name, major);
        this.stipend = stipend;
    }

    public void setStipend(double stipend) 
    {
        this.stipend = stipend;
    }

    public double getStipend() 
    {
        return stipend;
    }
}

/* Main class for creating object of GraduateStudent class to test the code*/
public class Main 
{
    public static void main(String[] args) 
    {
        GraduateStudent g = new GraduateStudent("John", "Computer", 1500);

        // calling GraduateStudent methods
        System.out.println(g.getName());
        System.out.println(g.getMajor());
        System.out.println(g.getStipend());
    }
}

Output:

I hope you got the provided solution.

Thank You.