java - 如何打印/引用第 7 号人物？

Question

如何打印/引用第 7 号人员？谢谢!

我已经尝试了多种方法，但是我无法引用第 7 个人。我是数组新手，明天到期，所以任何帮助都会很棒。我看了 youtube 上的一些教程，但我就是不明白出了什么问题？重新定义数组的方式与我看到的示例不同。

import java.text.*;           // to use Decimal Format

public class TwoD_ArrayDriver

{

   public static void main(String[] args)

   {

       DecimalFormat myFormat;

       // to get 2 decimals every time

       myFormat = new DecimalFormat("#.00");



       Person p1, p2, p3, p4, p5, p6, p7, p8, p9, p10, p11, p12, p13, p14, p15, p16, p17, p18, p19, p20, p21;

       p1 = new Person("Abby", "Arthur"); p2 = new Person("Bubba","Brown"); p3 = new Person("Chuckie", "Cheese"); p4 = new Person("Don", "Drysdale"); p5 = new Person("Ernie","Eastwood");

       p6 = new Person("Flo", "Fauntroy"); p7 = new Person("Gabby", "Giffords"); p8 = new Person("Hank","Hoover"); p9 = new Person("Indy", "Imhauf"); p10 = new Person("Jim","Jones");

       p11 = new Person("Ken", "Koopman"); p12 = new Person("Larry", "Lancelot"); p13 = new Person("Michael", "Moore" ); p14 = new Person("Nina","Nonesuch"); p15 = new Person("Oscar","OToole");

       p16 = new Person("Pat","Pompous"); p17 = new Person("Quincy","Quinton"); p18 = new Person("Ralph","Rancid"); p19 = new Person("Steven","Simpson"); p20 = new Person("Tim","Tinker");

       p21 = new Person("Uncle","Usher");

       Person[] allPersons = {p1, p2, p3, p4, p5, p6, p7, p8, p9, p10, p11, p12, p13, p14, p15, p16, p17, p18, p19, p20, p21};

       Person[] mondayAppts = {p1, p2, p3, p4, p5};

       Person[] tuesdayAppts = {p6, p7, p8};

       Person[] wednesdayAppts = {p9, p10, p11, p12};

       Person[] thursdayAppts = {p13, p14, p15, p16, p17};

       Person[] fridayAppts = {p18, p19, p20, p21};



       //Task #1 Print the id, first name, and last name of Person #7, using tuesdayAppts

       int intToPrint = 0;

       String fNameToPrint = "unknown";

       String lNameToPrint = "unknown";

       System.out.println("Person #7 "+intToPrint+" "+fNameToPrint+" "+lNameToPrint);

Answer 1

由于您尝试通过 tuesdayAppts 作为 Person[] tuesdayAppts = {p6, p7, p8}; 访问变量 p7 ，您应该执行 tuesdayAppts[1]，因为它位于数组的第二个位置。

示例(输出:Person #2 BBB bbb)

class Person {
    
    private static int idGen = 0;
    private int id;
    private String firstName;
    private String lastName;
    
    public Person(String firstName, String lastName) {
        this.firstName = firstName;
        this.lastName = lastName;
        this.id = ++Person.idGen;
    }

    public String toString() {
        return "Person #" + this.id + " " + this.firstName + " " + this.lastName;
    }
    
}

class Example {
    
    public static void main(String[] args) {
        Person a, b, c;
        a = new Person("AAA", "aaa");
        b = new Person("BBB", "bbb");
        c = new Person("CCC", "ccc");
        Person[] personArray = {a, b, c};
        System.out.println(personArray[1]);
    }
    
}