[1] Packages, which were briefly described in Step 1 in Chapter 2, will be covered in depth inChapter 13.
[2] figuratively speaking
[3] Overloaded methods have the same name but different argument types. More on method overloading in Section 6.11.
[4] All is not necessarily lost, however. There is an extremely slight chance your program with the *p might compile as C++.
[5] The bitwise-xor method performs an exclusive or on its operands. Identical bits yield a 0. Different bits yield a 1. Thus 0011 ^ 0101 yields 0110.
[6] The leftmost bit in an integer type is the sign bit. If the leftmost bit is 1, the number is negative. If 0, the number is positive.
[7] The automatic check does not look at the right-hand side, but any reasonable equalsmethod should return false if its argument is null.
[8] By now you should be able to figure out that given this code, the Scala compiler would invoke (bills.!*&^%~(code)).!().