Person.java 引数にVehicle型の値を受け取るbuyメソッドを新たに定義する。

class Person {
private String firstName;
private String middleName;
private String lastName;
private int age;
private double height;
private double weight;

Person(String firstName, String lastName, int age, double height, double weight) {
this.firstName = firstName;
this.lastName = lastName;
this.age = age;
this.height = height;
this.weight = weight;
}

Person(String firstName, String middleName, String lastName, int age, double height, double weight) {
this(firstName, lastName, age, height, weight);
this.middleName = middleName;
}

public String fullName() {
if (this.middleName == null) {
return this.firstName + " " + this.lastName;
} else {
return this.firstName + " " + this.middleName + " " + this.lastName;
}
}

public void printData() {
System.out.println("名前は" + this.fullName() + "です");
System.out.println("年齢は" + this.age + "歳です");
System.out.println("身長は" + this.height + "mです");
System.out.println("体重は" + this.weight + "kgです");
System.out.println("BMIは" + Math.round(this.bmi()) + "です");
}

public double bmi() {
return this.weight / this.height / this.height;
}

// 以下2つを一つのメソッドで書き換えてください
public void buy(Vehicle vehicle){
vehicle.setOwner(this);
}
}