OOP 2

public class Test {
    public static void main(String[] args) {
        Teacher[] teachers = new Teacher[5];

        teachers[0] = new Teacher("Boyan", "0929929", new Subject("Math"));
        teachers[1] = new Teacher("Mitko", "07213", new Subject("Chemistry"));
        teachers[2] = new Teacher("Asen", "09876", new Subject("Geography"));
        teachers[3] = new Teacher("Stilian", "08830", new Subject("Physics"));
        teachers[4] = new Teacher("Blagoy", "07712", new Subject("History"));

        for (Teacher s : teachers) {
            System.out.println(s.getName());
            System.out.println(s.getSubject().getSubjectname());
        }

        if (hasSubject(new Subject("Math"), teachers)) {
            System.out.println("I have a Math teacher");
        } else {
            System.out.println("I don't have a Math teacher");
        }

        if (hasSubject(new Subject("Biology"), teachers)) {
            System.out.println("I have a Biology teacher");
        } else {
            System.out.println("I don't have a Biology teacher");
        }

        if (hasSubject(new Subject("History"), teachers)) {
            System.out.println("I have a History teacher");
        } else {
            System.out.println("I don't have a History teacher");
        }

        if (hasSubject(new Subject("Physics"), teachers)) {
            System.out.println("I have a Physics teacher");
        } else {
            System.out.println("I don't have a Physics teacher");
        }
    }
    public static boolean hasSubject(Subject subject, Teacher[] arr){
        for (Teacher s:arr) {
            if(s.getSubject().getSubjectname().equals(subject.getSubjectname())){
                return true;
            }
        }
        return false;
    }
}

public class Person {
    private String name;
    private String egn;

    public Person(){
        this.name = "";
        this.egn = "";
    }
    public Person(String name ,String egn){
        this.name = name;
        this.egn= egn;
    }
    public String getName() {
        return this.name= name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public String getEgn() {
        return this.egn = egn;
    }
    public void setEgn(String egn) {
        this.egn = egn;
    }
}

public class Student extends Person {
    public String fNum;

    public Student() {
        super();
        this.fNum = "";
    }
    public Student(String name, String egn, String fNum) {
        super(name, egn);
        this.fNum = fNum;
    }
    public String getfNum() {

        return this.fNum = fNum;
    }
    public void setfNum(String fNum) {

        this.fNum = fNum;
    }
    public static void sayHi() {
        System.out.println("Hello");
    }
    public void printFnum() {
        System.out.println("My Fnum is:" + this.fNum);
    }
}

public class Subject {
    private String subjectname;

    public Subject(String name) {
        this.subjectname = name;
    }
    public String getSubjectname() {
        return subjectname;
    }
    public void setSubjectname(String subjectname) {
        this.subjectname = subjectname;
    }
}

public class Teacher extends Person {
    private Subject subject;

    public Teacher(Subject subject) {

        this.subject = subject;
    }
    public Teacher(String name, String egn, Subject subject) {
        super(name, egn);
        this.subject = subject;
    }
    public Subject getSubject() {

        return subject;
    }
    public void setSubject(Subject subject) {

        this.subject = subject;
    }
}