Question

How does the this pointer points to the object itself? Is it a java implementation or is it a compiler implementation?

Answer 1

Well if you are interested why not look at the byte code generated by the compiler

class HelloWorld
{
   private String hello = "Hello world!";

   private void printHello(){
   System.out.println (this.hello);
}

public static void main (String args[]){
  HelloWorld hello = new HelloWorld();
  hello.printHello();
}

}

Compile using

%JAVA_HOME%/bin/javac HelloWorld.java

Get bytecode using

javap -c HelloWorld

edit add output

enter code here

 HelloWorld();
 Code:
 0:   aload_0
 1:   invokespecial   #1; //Method java/lang/Object."<init>":()
 4:   aload_0
 5:   ldc     #2; //String Hello world!
 7:   putfield        #3; //Field hello:Ljava/lang/String;
 10:  return

 public static void main(java.lang.String[]);
 Code:
 0:   new     #6; //class HelloWorld
 3:   dup
 4:   invokespecial   #7; //Method "<init>":()V
 7:   astore_1
 8:   aload_1
 9:   invokespecial   #8; //Method printHello:()V
12:  return

}