constant
1. Constant variables modified by const
2. Identifier constant defined by #define
3. Enumeration constant
Enumeration: enumerate one by one
eg:
gender: male, female
Week: 1, 2, 3, 4, 5, 6, 7
Keywords: enum
Enumeration: enumerate one by one
eg:
gender: male, female
Week: 1, 2, 3, 4, 5, 6, 7
Keywords: enum