Original article address:Convert: char *,
Char []
, Cstring,
String Conversion
Author:Gisldq
(1) OverviewString and cstring are both string template classes. string is a string class defined by the standard template class (STL) and has been
Ansi c provides three types of characters: Char, signed Char, and unsigned char. There are only two types of characters like short and INT (INT is unsigned int by default ).
Each of the three occupies 1 byte. Therefore:
The value range of signed
The transformation between string,cstring,char*
int Turn CString:Cstring.format ("%d", int);...............................String Turn CStringCstring.format ("%s", String.c_str ());Using C_str () is indeed better than data ()........................
Binary negative Number:The original code is the original representation methodAnti-code is the inverse of the sign bit (highest bit)Complement = anti-code +1 1 bytes It can only represent 256 numbers anyway, because there is a sign, so we're going
Charvarcharvarchar2 differences: 1. the length of CHAR is fixed, while the length of VARCHAR2 can be changed. For example, the storage string "abc", for CHAR (20 ), it indicates that the characters you store will occupy 20 bytes (including 17 null
Reprint Address: http://hi.baidu.com/thewillreigns/blog/item/67e665c4296e69c038db492d.html
Char and unsigned char are unsignedBoth are used words as words that are indistinguishable, but when integers are used differently:Char integer range is-128
Cstring, Int, String, char * ConversionString to cstringCstring. Format ("% s", String. c_str ());Convert Char to cstringCstring. Format ("% s", char *);Char to stringString S (char *);String to char *Char * P = string. c_str ();Cstring to
Char varchar varchar2 the difference http://blog.csdn.net/honglei_zh/article/details/7172538Difference:1. The length of the char is fixed, and the length of the VARCHAR2 is changeable, for example, storing the string "abc", for Char (20), which
Comparison of data typesChar represents a fixed length, and the longest n-word varchar represents the actual length of the data type, such as: if it is a char type, when you enter a character that is less than the length, then a space is added, but
Char-type numeric conversion, char-type numeric ConversionChar type numeric Conversion
In the video tutorial, you have learned how to convert numbers, strings, and other types. In some cases, we also need to convert the char type to the int type, or
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