Chapter 10

• We are starting chapter 10.
  • you should read it.
  • That is not a suggestion.
• The chapter begins by reviewing the different data types you know.
• 
• A simple or atomic data type is a datatype where each value is atomic or indivisible
  • floats and ints are examples of this.
• A structured data type is a data type where each value is a collection of components whose organization is characterized by the method used to access individual components.
  • Strings are an example of this.
  • The components are the different letters.
  • .at() or [] can be used to access these individual letters.
• When discussing data types, we frequently discuss
  • The domain or the set of values the data type can hold
  • The operations or the things you can do to a data type.
• Consider the type bool
  • The domain is true and false.
  • The operations are
    • Boolean operators (and, not, or)
    • Comparison
  • Consider the integers
    • The domain is INT_MIN to INT_MAX
      • Look at /usr/incude/limits.h
    • The operations are
      • +,-,*,/
      • Comparison
      • input and output
  • Characters are strange
    • The domain is CHAR_MIN to CHAR_MAX
    • Operations are the same as the integer.
    • But they have a different internal representation from their external representation.
      • Internal representation is how they are stored (ascii value)
      • External representation is how it is presented externally (cout, ...)
• C++ allows us to create user defined data types.
• Typedef
  • Not really a user defined type, just giving a nickname to an existing type.
  • Syntax: typedef old_type new_type
  • Example: typedef unsigned long long int BigNumT
  • typedef allows us to
    • Rename a difficult type name (unsigned long long int) to something easier to remember.
    • Establish abstractions
      • size_type
      • See this reference or page 467 of your book.
      • This means a properly written program can experience a change in the size of string provided by the a different compiler with just a recompile.
  • See fact.cpp