c语言语法

工作了才知道，原来c语言也还如此陌生，只知道一些常用的用法，却对稍微有点不常见的就不清楚了，从今天起，开始整理！

typedef

The formula to follow is:      typedef [attributes] DataType AliasName;

      example：

                  typedef short SmallNumber;
                  typedef unsigned int Positive;
                  typedef double* PDouble;
                  typedef string FiveStrings[5];

     mean:

                 In typedef short SmallNumber, SmallNumber can now be used as a data type to declare a variable for a small integer.
                 In the second example, typedef unsigned int Positive, The Positive word can then be used to declare a variable of an unsigned int type.
                 After typedef double* PDouble, the word PDouble can be used to declare a pointer to double.
                 By defining typedef string FiveStrings[5], FiveStrings can be used to declare an array of 5 strings with each string being of type string.