Identifiers

• Names of things in a C++ program
• A character followed by 0 or more digits or characters
• Characters are a-z,A-Z and _
• You should not start identifiers with a _
• Some good identifiers
  • A
  • i
  • aword
  • name
  • first_name
  • __hpux
  • name1
• Some bad identifiers
  • 4days
  • name+age
  • int
• There are a number of special words in C++ called Reserved Words.
  • These have special meaning to the compiler
  • They are listed in appendix A.
  • You shouldn't use them as identifiers.
• Your names should
  • Have meaning
  • Be descriptive
  • Not be too long
  • Be described.
  • Some examples:
    • Net_Pay
    • username
    • FirstName
  • I prefer
    • Mix upper and lower case.
    • Use underscore.
    • Use full words when it applies.
  • Case matters. The following are all different.
    • DataIn
    • Datain
    • datain
    • DATAIN
  • Selecting good names for your identifiers is a first step in writing good self documenting code.