Java assignment solutions

Aggregation is a relationship between two classes like association, however its a directional association, which means it is strictly a one way association.For example consider two classes Student class and Address class. each student must have an address so the relationship between student and address is a relationship. But if you consider its vice versa then it would not make sense as an Address doesn’t need to have a Student necessarily. Below example shows this theoretical explanation in a sample java program.

class Address

{

   int streetNum;

   String city;

   String state;

   String country;

   Address(int street, String c, String st, String coun)

   {

       this.streetNum=street;

       this.city =c;

       this.state = st;

       this.country = coun;

   }

}

class StudentClass

{

   int rollNum;

   String studentName;

   Address studentAddr;

   StudentClass(int roll, String name, Address addr){

       this.rollNum=roll;

       this.studentName=name;

       this.studentAddr = addr;

   }

   public static void main(String args[]){

       Address ad = new Address(69, "Gautam Budh road", "Delhi", "India");

       StudentClass obj = new StudentClass(619, "Rey Mysterio", abc);

       System.out.println(obj.rollNum);

       System.out.println(obj.studentName);

       System.out.println(obj.studentAddr.streetNum);

       System.out.println(obj.studentAddr.city);

       System.out.println(obj.studentAddr.state);

       System.out.println(obj.studentAddr.country);

   }

}