方法之間的Java對象範圍

Question

我遇到了運行此代碼的問題，我試圖讓程序使用來自其他類的輸入來打印下面的字符串。正如你所看到的，放入新娘和新位置對象的信息將被放入婚禮對象中，然後我需要嘗試從婚禮對象中檢索細節並將其顯示在屏幕上，如下所示：

Wedding data:
Bride: Amy Cronos, age: 29
Location: South Rd, suburb: Tonsley

但我不是遇到了與該place.getName，place.getSuburb（）等等，等等這說

Main.java:6: error: cannot find symbol System.out.println("Location"+place.getStreet()+", suburb:
"+place.getsuburb());

symbol: variable place

location: class Main

我敢肯定，這事做與範圍的4級相同的錯誤，但無法解決我需要做的事情。

什麼是導致這個錯誤，我該如何解決它？

下面是代碼：

public class WeddingDetails { 

    public static void main(String[] args) { 

     Bride person = new Bride("Amy Cronos", 29); 
     Location place = new Location("Tonsley", "South Rd"); 
     Wedding wed = new Wedding(person, place); 
     show(wed); 
    } 

    public static void show(Wedding wed) { 
     System.out.println("Wedding data:"); 
     System.out.println("Bride: " + person.getName() + ", age: " + person.getAge()); 
     System.out.println("Location: " + place.getStreet() + ", suburb: " + place.getSuburb()); 

    } 

    public static class Location { 

     private String suburb; 
     private String street; 

     Location(String suburb, String street) { 
      this.suburb = suburb; 
      this.street = street; 
     } 

     public String getSuburb() { 
      return suburb; 
     } 

     public String getStreet() { 
      return street; 
     } 
    } 

    public static class Bride { 

     private String name; 
     private int age; 

     Bride(String name, int age) { 
      this.name = name; 
      this.age = age; 
     } 

     public String getName() { 
      return name; 
     } 

     public int getAge() { 
      return age; 
     } 

    } 

    public static class Wedding { 

     private Bride person; 
     private Location place; 

     Wedding(Bride person, Location place) { 
      this.person = person; 
      this.place = place; 

     } 

     public Bride getBride() { 
      return person; 
     } 

     public Location getPlace() { 
      return place; 
     } 
    } 
} 

Answer 1

問題這裏是你的println語句試圖對象中的訪問方法，但通過調用錯了對象上的方法。您應該使用Wedding類的getters（getBride（）和getPlace（）來訪問新娘和位置對象。完整的調用將是wed.getBride（）。getName（）和wed.getPlace（）。getStreet（）等等。

修正代碼如下注：爲能夠編譯所有代碼的一個類內部的目的，我加入了static關鍵字新娘，位置和婚慶類聲明你可以只取出static和。複製和每個班級粘貼到您的.java文件

public class WeddingDetails { 

    public static void main(String[] args) { 

     Bride person = new Bride("Amy Cronos", 29); 
     Location place = new Location("Tonsley", "South Rd"); 
     Wedding wed = new Wedding(person, place); 
     show(wed); 
    } 

    public static void show(Wedding wed) { 
     System.out.println("Wedding data:"); 
     System.out.println("Bride: " + wed.getBride().getName() + ", age: " + wed.getBride().getAge()); 
     System.out.println("Location: " + wed.getPlace().getStreet() + ", suburb: " + wed.getPlace().getSuburb()); 

    } 

    public static class Location { 

     private String suburb; 
     private String street; 

     Location(String suburb, String street) { 
      this.suburb = suburb; 
      this.street = street; 
     } 

     public String getSuburb() { 
      return suburb; 
     } 

     public String getStreet() { 
      return street; 
     } 
    } 

    public static class Bride { 

     private String name; 
     private int age; 

     Bride(String name, int age) { 
      this.name = name; 
      this.age = age; 
     } 

     public String getName() { 
      return name; 
     } 

     public int getAge() { 
      return age; 
     } 

    } 

    public static class Wedding { 

     private Bride person; 
     private Location place; 

     Wedding(Bride person, Location place) { 
      this.person = person; 
      this.place = place; 

     } 

     public Bride getBride() { 
      return person; 
     } 

     public Location getPlace() { 
      return place; 
     } 
    } 
}