眾所周知,Scala 是運行於Java平臺（Java虛擬機器）的,那麼Scala程式編譯之後會生成對應的位元組碼檔案,我們將位元組碼檔案反編譯成Java檔案即可知Scala 為我們都做了什麼.

1. 首先我們有一個Scala 原始檔

   //Scala原始碼
   class Test3 {
     val a = "a"
     var b = "b"
   
     private val c = "c"
     private var d = "d"
   
     private[this] val e = "e"
     private[this] var f = "f"
   
     @BeanProperty var g = "g"
     @BeanProperty
    
    val h = "h"
   }

2. 那麼接下來我們看看這些屬性在反編譯成JAVA原始碼Scala都幫我們做了什麼

   //反編譯後的程式碼
   public class Test3
   {
     private final String a = "a";
     private String b = "b";
   
     private final String c = "c";
     private String d = "d";
   
     private final String e = "e";
     private String f = "f";
   
     @BeanProperty
     private String g = "g"
    
   ;
   
     @BeanProperty
     private final String h = "h";
   
     public String a() { return this.a; } 
     public String b() { return this.b; } 
     public void b_$eq(String x$1) { this.b = x$1; } 
   
     private String c() { return this.c; } 
     private String d() { return this.d; } 
     private void d_$eq(String x$1) { this
    
   .d = x$1; }
   
     public String g() {return this.g; } 
     public void g_$eq(String x$1) { this.g = x$1; } 
     public String h() { return this.h; }
     public String getG(){return g(); } 
     public String getH() { return h(); }
     public void setG(String x$1){g_$eq(x$1);}
   }

   總結下:

   Scala欄位	生成的方法
   val/var name	公共的name name_ 方法(僅限於var)
   prviate val/var name	私有的name name_ 方法(僅限於var)
   prviate[this] val/var name	無
   @BeanProperty val/var name	公共的name getName() name_ setName(…)(僅限於var)