Class exercise: what will be displayed?
class Swapper {
public void methodA(int x, int y) {
int temp = x;
x = y;
y = temp;
}
public void methodB(int[] a) {
int temp = a[0];
a[0] = a[1];
a[1] = temp;
}
}
class SwapTester {
public static void main(String[] args) {
Swapper sw = new Swapper();
int[] numbers = {25, 14};
System.out.println(numbers[0] + " " + numbers[1]);
sw.methodA(numbers[0], numbers[1]);
System.out.println(numbers[0] + " " + numbers[1]);
sw.methodB(numbers);
System.out.println(numbers[0] + " " + numbers[1]);
}
}
Example
class Student {
String name;
Lecturer supervisor;
public Student(String s) {
name = s;
}
public void setSupervisor(Lecturer sprvsr) {
supervisor = sprvsr;
}
}
class Lecturer {
String name;
Student[] supervisees;
public Lecturer(String s) {
name = s;
supervisees = new Student[3];
}
public void addSupervisee(Student stdnt) {
for (int i = 0; i < 3; i = i + 1) {
if (supervisees[i] == null) {
supervisees[i] = stdnt;
break;
}
}
}
}
class UniTester {
public static void main(String[] args) {
Lecturer lect = new Lecturer("Dr Guy Dance");
Student stud1 = new Student("Mr Reggie Mental");
Student stud2 = new Student("Ms Anna Key");
stud1.setSupervisor(lect);
lect.addSupervisee(stud1);
stud2.setSupervisor(lect);
lect.addSupervisee(stud2);
}
}