Assume that the following classes have been defined:
public class Poe extends Kylo {
public void method2() {
super.method2();
print("Poe 2 ");
}
public String toString() {
return "Poe " + super.toString();
}
}
public class Kylo extends Finn {
public void method1() {
print("Kylo 1 ");
}
public String toString() {
return "Kylo";
}
}
public class Finn extends Rey {
public void method2() {
print("Finn 2 ");
method1();
}
}
public class Rey {
public String toString() {
return "Rey";
}
public void method1() {
print("Rey 1 ");
}
public void method2() {
print("Rey 2 ");
}
}
Given the classes above, what output is produced by the following code? (Since the code loops over the elements of an array of objects, write the output produced as the loop passes over each element of the array separately.)
Rey[] elements = { new Finn(), new Rey(), new Poe(), new Kylo() };
for (int i = 0; i < elements.length; i++) {
println(elements[i]);
elements[i].method1();
println();
elements[i].method2();
println();
println();
}
Kylo-1
The output produced by the given code when it loops over each element of the array is as follows:
1. For the first element (new Finn()):
Rey
Rey 1
Rey 2
2. For the second element (new Rey()):
Rey
Rey 1
Rey 2
3. For the third element (new Poe()):
Poe Rey
Rey 1
Finn 2
Kylo 1
Poe 2
4. For the fourth element (new Kylo()):
Kylo Rey
Rey 1
Finn 2
Kylo 1
Poe 2
To determine the output produced by the given code, we need to trace the execution of each iteration of the loop. Let's go through the loop and its iterations step by step.
Iteration 1:
- The loop starts with `i = 0`.
- `elements[0]` is an instance of `Finn`, so the output is `Rey`, followed by `Rey 1` (as method1() is called).
- Then, `method2()` is called on `elements[0]`, which outputs `Finn 2` and subsequently calls `method1()` and outputs `Kylo 1`.
- Two blank lines are printed.
Iteration 2:
- `i` is incremented to `1`.
- `elements[1]` is an instance of `Rey`, so the output is `Rey`, followed by `Rey 1`.
- Then, `method2()` is called on `elements[1]`, which outputs `Rey 2`.
- Two blank lines are printed.
Iteration 3:
- `i` is incremented to `2`.
- `elements[2]` is an instance of `Poe`, which extends `Kylo`. So, `method1()` is called on `elements[2]`, which outputs `Kylo 1`.
- Then, `method2()` is called on `elements[2]`, which first calls `super.method2()`, i.e., `method2()` of `Kylo` which outputs `Finn 2` and then calls `method1()`, which outputs `Kylo 1`.
- Two blank lines are printed.
Iteration 4:
- `i` is incremented to `3`.
- `elements[3]` is an instance of `Kylo`, which extends `Finn`. So, `method1()` is called on `elements[3]`, which outputs `Kylo 1`.
- Then, `method2()` is called on `elements[3]`, which outputs `Finn 2` and then calls `method1()`, which outputs `Kylo 1`.
- Two blank lines are printed.
Therefore, the final output produced by the code is:
```
Rey
Rey 1
Rey 2
Rey
Rey 1
Rey 2
Rey
Kylo 1
Finn 2
Kylo 1
Rey
Kylo 1
Finn 2
Kylo 1
```
Note: The output may vary depending on the exact implementation of the `print()` and `println()` methods.