爲什麼非靜態方法有額外的本地？還有，這是什麼？

Question

根據我對方法1中的每個局部變量定義的理解，爲本地人指示符添加了局部變量。

來源：

public class A { 
    public void a() {} 

    public static void b() {} 
} 

生成的字節碼：

Compiled from "A.java" 
public class A extends java.lang.Object 
    SourceFile: "A.java" 
    minor version: 0 
    major version: 50 
    Constant pool: 
const #1 = Method  #3.#12; // java/lang/Object."<init>":()V 
const #2 = class  #13; // A 
const #3 = class  #14; // java/lang/Object 
const #4 = Asciz  <init>; 
const #5 = Asciz  ()V; 
const #6 = Asciz  Code; 
const #7 = Asciz  LineNumberTable; 
const #8 = Asciz  a; 
const #9 = Asciz  b; 
const #10 = Asciz  SourceFile; 
const #11 = Asciz  A.java; 
const #12 = NameAndType #4:#5;// "<init>":()V 
const #13 = Asciz  A; 
const #14 = Asciz  java/lang/Object; 

{ 
public A(); 
    Code: 
    Stack=1, Locals=1, Args_size=1 
    0: aload_0 
    1: invokespecial #1; //Method java/lang/Object."<init>":()V 
    4: return 
    LineNumberTable: 
    line 1: 0 


public void a(); 
    Code: 
    Stack=0, Locals=1, Args_size=1 
    0: return 
    LineNumberTable: 
    line 6: 0 


public static void b(); 
    Code: 
    Stack=0, Locals=0, Args_size=0 
    0: return 
    LineNumberTable: 
    line 11: 0 


} 

Answer 1

這是當前對象，也叫做this。從the JVM Spec §3.6.1 Local Variables：

在實例方法調用，局部變量0總是被用來傳遞（在Java編程語言this），以在其上被調用的實例方法的對象的引用。

Answer 2

我的猜測是，它的this