File name

  • fully lower-case
  • word separation expressed as _ (underscore)
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file_name.txt    
very_good_source_code.c

Type name

  • start with capital letter
  • next letters are lower-case
  • word separation expressed as upper-cased first letter
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class SuperDuperClass{};
struct TypeNameExpressedLikeThis{};

Variable name

  • function parameters are included in variable

  • Common variable name

    • fully lower-case
    • space expressed into _ (underscore)
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    int integer_variable = 4;    
int quantity_of_cookies = 0;

  • Class data member name

    • same with common variable name, but has tailing _ (underscore)
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    class SampleClass    
{    
private:   
    int class_member_;    
    float x_, y_;    
};

  • Struct data member name

    • fully same with common variable name
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    struct SampleStruct    
{
    int struct_member;    
    float x, y;    
};

Constant name

  • start with k
  • word separation expressed as upper-cased first letter
  • if you can’t use uppercase spacing, _ (underscore) is allowed that time
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const int kMagicNumber = 42;    
const int kAndroid8_0_0 = 24;

Function name

  • start with capital letter
  • word separation expressed as upper-cased first letter
  • some functions like accessors and mutators can be named like variable.
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MoveToThere();
ScoreCount();
get_name();
set_name();
size();

NameSpace name

  • fully lower-case
  • word separation expressed as _ (underscore)
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namespace countryside_bus {}
namespace project_goo {}

Enumerator name

  • enum follows Constant naming rule
  • not Macro naming rule
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enum Fruits {
    kBanana,
    kApple,
    kCherry
};

Macro name

  • fully CAPITAL LETTER
  • word separation expressed as _ (underscore)
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#define PI 3.14
#define ARRAY_SIZE 32

Some Exceptions

If you are naming something that is analogous to an existing C or C++ entity then you can follow the existing naming convention scheme.

  • bigopen()
    • function name, follows form of open()
  • uint
    • typedef
  • bigpos
    • struct or class, follows form of pos
  • sparse_hash_map
    • STL-like entity; follows STL naming conventions
  • LONGLONG_MAX
    • a constant, as in INT_MAX