Java String Constant Pool - Number of Objects Created

Question

How many string objects will be created by the following code?

String s = "Mahendra" + "Singh" + "Dhoni";

Will it create 4 string objects in the string pool or will it create more than that? Please explain in detail.

P.S. I have seen other examples and they deal only for 2 string objects.

EDIT : I see from the answers that in above case only 1 object will be created. Thanks a lot for some very good suggestions. Sorry to ask a stupid question but can you please tell in the below case how many objects will be created?

String s = "Mahendra";
s = s + "Singh" + "Dhoni";

2nd EDIT : Sorry again but I still have some doubt. I see in the comments that in the above case 3 objects will be created "Mahendra", "SinghDhoni" and "MahendraSinghDhoni". My doubt is shouldn't it be calculated from the left to right. Am I missing something - concept wise? Please help.

Also, in another case, if I twist this question, how will the number of objects change. I am asking this as in detail to clear it for lot of my colleagues as well. All the help is appreciated.

String s = "Singh";
s = "Mahendra" + s + "Dhoni";

Answer 1

If your code was :

public static void main(String[] args) {
    String s = "Mahendra" + "Singh" + "Dhoni";
    System.out.println(s);
}

Look at the byte code :

 public static void main(java.lang.String[]);
   descriptor: ([Ljava/lang/String;)V
   flags: ACC_PUBLIC, ACC_STATIC
   Code:
     stack=2, locals=2, args_size=1
        0: ldc           #16                 // String MahendraSinghDhoni --> This line
        2: astore_1
        3: getstatic     #18                 // Field java/lang/System.out:Ljav
/io/PrintStream;
        6: aload_1
        7: invokevirtual #24                 // Method java/io/PrintStream.prin
ln:(Ljava/lang/String;)V
       10: return

As you see the compiler is adding All three strings during compile time. So there will be only one string on the String constants pool thats all.

EDIT : based on the edited question :

"Singh" + "Dhoni" will be added during compile time. So there will be totally 3 String objects. "Mahendra" and "SinghDhoni" will be on String constants pool and then mahendraSinghDhoni will be on heap.

Answer 2

This will create only 1 string s in string pool. Please read the difference bwt String object and literal it will help you understand.