When I new a Hashtable, why the put method is invocated?

Question

I am reading the code of Hashtable and am confused and have some questions. I coded like this:

Hashtable table = new Hashtable();
table.put(table, 1);
int code = table.hashCode();

I have two questions:

1. When I invoke the hashCode method just like the third line code, why isn't it an endless loop? I think it is an endless loop.

2. When I debug this code, I found that code new Hashtable() will cause the invocation of put method, why?

Answer 1

1. According to the OpenJDK source I'm reading, there's a guard written specifically to guard against the case where a Hashtable contains itself.

2. I don't see any reference to put within the constructor. Do you have a trace you could post in your answer?