understanding the java string with add operator

Question

I am trying to understand how the compiler views the following print statements. It is simple yet a bit intriguing.

This prints the added value. Convincing enough.<

Answer 1

I also found this interesting. I haven't worked too much in java recently but I found out a little bit of info that might be helpful through playing with it.

I think this has to do with automatic Type-casting that java does.

System.out.println("1"+2+3);

Prints 123 as you said. Since "1" is casted as string, Java assumes since the first one was a string, the ones following will be a string for concatenation unless otherwise noted

Although, this result does print 15 when you define the type

System.out.println("1" + (int)(2+3));

In that case, it can complete the operation before concatenating.

So I think java is assuming if the first one is a String, that the rest are going to be strings and to concatenate them.

EDIT: you can see some info about automatic type-conversion on oracle's website here