12.1 Modifying Variables

      12.1.1 Modifying Variables in Memory

      12.1.2 Variable Updates and Aliasing

      12.1.3 Updating Variables versus Updating Data Fields

      12.1.4 Updating Parameters in Function Calls

      12.1.5 Updating Top-Level Variables within Function Calls

      12.1.6 The Many Roles of Variables

    12.2 Mutable Lists