import java.io.*;
public class MyData {
public static void main(String[] args) {
//Student aStudent = new Student();
Student bStudent = new Student("1234567","John", "12 Wick St Redwood","2344","08/08/1986","95066713");
bStudent.printStudent();
}
}
class Student{
private String number;
private String name;
//private boolean male;
private String address;
private int post;
private Date dob; // not yet instantiated
private String phone;
//private double marks[] = null;
Student(){ // default constructor
System.out.println("Student Created");
}
Student(String number, String name, String address, String post, String dobString, String phone){ // constructor
this.number = number;
this.name = name;
this.address = address;
this.post = Integer.parseInt(post); // convert string to int.
Date dob = new Date(dobString); // intialize dob object
this.phone = phone;
dob.printDob(); // Here You are not getting error because you are using
//Date object that is initialized at line 30
// If you put this, you will not get any error
this.dob = dob;
}
void printStudent(){
System.out.println(number);
System.out.println(name);
System.out.println(address);
System.out.println(post);
dob.printDob(); // Here dob object is null, because in this case
//the dob Object is referencing to Object that defined on
// line number 17 and is not initiantiated. It is NULL.
System.out.println(phone);
}
}
class Date{
int day, month, year;
Date(){ // default constructor
day = 0;
month = 0;
year = 0;
}
Date(String dobString){
String input[] = new String[10]; // for storing day month year
String patternStr = "/"; // character to split line at.
input = dobString.split(patternStr);
day = Integer.parseInt(input[0]); // convert string to int.
month = Integer.parseInt(input[1]);
year = Integer.parseInt(input[2]);
}
void printDob(){ // to print out date of birth
System.out.println(day + "/" + month + "/" + year); //format dd/mm/yyyy
}
}