Why this is not working...?

import java.util.*; public class Family {

int size_of_family=0;

public Person[] members=new Person[size_of_family];
 Person d = new Person();

public Family (int size_of_family){

    members = new Person[size_of_family]; 

    for ( int i = 0; i < size_of_family; ++i )
      {
         members[i] = new Person();

    System.out.println(members[i]);
      } 
}
public void printOutFamily(){

    for (int i = 0; i < size_of_family; ++i)
        System.out.println(members[i]);

    }


public void addPerson(Person p){
      d = new Person();
    for( int i=0; i <members.length; i++){          
    if(!members[i-1].equals(d)){
          members[i-1]=d;
    }
        else{
            System.out.println("This person already exist");
        }

    }
    }



    public static void main(String[] args)
    {
       Person fred= new Person("Fred Flintstone", 50);
       System.out.println("created " + fred);

       Person wilma = new Person("Wilma Flintstone", 48);
       student george= new student("George Flintstone", 21, "Politics", 3.1);
       System.out.println("created " + george);

       student sue= new student("Sue Flintstone", 24, "Nursing", 3.3);
       student anotherGeorge= new student("George Flintstone", 21, "Math", 3.4);
       Person yetAnotherGeorge= new Person("George Flintstone", 50);

       Family f = new Family(10);
       f.addPerson(fred);
       f.addPerson(wilma);
       f.addPerson(george);
       f.addPerson(sue);
       f.addPerson(anotherGeorge);
       f.addPerson(yetAnotherGeorge);

       anotherGeorge.setName("Georgie Flintstone");
       f.addPerson(anotherGeorge);

       f.printOutFamily();

    }

}

View Answers

April 4, 2012 at 4:59 PM

Post the code of Student.java and Person.java files.

April 4, 2012 at 5:31 PM

public class Person {

private String name;
private int age;

public Person(){
     name="No name";
     age=0;
}

public Person(String theName,int theAge){
    this.name=theName;
    this.age=theAge;
}
public String getName(){
    return name;
}

public void setName(String theName){
    name=theName;
}
public int getAge(){
    return age;
}
public void setAge(int theAge){
    age=theAge;

}

public String toString(){
    return( getName().toString()+"  " + age);

}
public boolean equals(Person otherPerson){
    return (name.equals(otherPerson.name) && age==(otherPerson.age));

}

}

April 4, 2012 at 5:31 PM

public class student extends Person { private String major; private double gpa;

public student(){
    super();
    major="Undeclared";
    gpa=0;
}
public student(String theName,int theAge,String theMajor,double theGPA){
        super(theName,theAge);
        this.major=theMajor;
        this.gpa=theGPA;

}
public String getMajor(){
    return major;
}

public void getMajor(String theMajor){
    major=theMajor;
}

public double getgpa(){ return gpa; } public void setgpa(double theGPA){ gpa=theGPA; }

public String toString(){
    return(getName()+"    "+ getAge()+"  " + major+"  "+ gpa ); 

}
public boolean equals(student  other){
    return(getName().equals(other.getName()) &&getAge()==(other.getAge())&& major==(other.major) && gpa==(other.gpa));


}

}

April 4, 2012 at 6:27 PM

Object class is the root of every class you create.Every class implicitly extends Object class.

for example:

    class cat {
            String colour;
        }

the same class can also be written as ....

    class cat extends Object {
        String colour
    }

April 4, 2012 at 9:55 PM

This is the output after i run the program!!!!!!

created Fred Flintstone  50

created George Flintstone    21  Politics  3.1

No name  0

No name  0

No name  0

No name  0

No name  0

No name  0

No name  0

No name  0

No name  0

No name  0

Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: -1
    at Family.addPerson(Family.java:31)
    at Family.main(Family.java:57)

Why this is not working...?

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