Unsigned char: unsigned character type, which can represent integers from 0 to 255, and can expand the range of data representation without involving negative numbers.
Int: integer data, which usually represents the length of memory bytes specified by the compiler-only integers of -32768~+32767 can be carried on the double-byte platform; Usually it is a 4-byte platform, which can carry integers of-2147483648 ~+2147483647.
Unsigned int (abbreviated as unsigned): an unsigned integer, which can represent an integer from 0 to 65535 on a double-byte platform; Integers from 0 to 4294967295 can be represented on a 4-byte platform. This type can expand the scope of data expression without negative participation.
Long int: Long integer, which is 4 bytes under the double-byte platform, and is the same as the current int type.
Float: Single-precision floating-point data, which belongs to one kind of floating-point data-4-byte floating-point data. The normalized expression range is 10-38 ~ 10+38, and the maximum effective precision is 7 digits. 8.888888 This number can be expressed by floating-point type.
Double: double-precision floating-point data, which belongs to one kind of floating-point data-8-byte floating-point data. The normalized expression range is plus or minus10-308 ~/kloc-0+308, and the maximum effective precision is 16 bits. 8.8888888 This number can be represented by a double.
Long double: Long double, 10 byte, 19 significant bit (not recognized by some compilation platforms).
Long long int or _ _ int 64: 8-byte integer, which has the same properties as int except that the byte length is twice as long as int. Not all compilation platforms are recognized.
Void: Declare that the function has no return value or/and parameters, and declare an untyped pointer to display the result of the discard operation.