Conversion between char *, Int, cstring, and string

1. Convert from char * to int

Char * Ch;

Int num;

Num = atoi (CH );

The details are as follows:

# Include <stdlib. h>
Int atoi (const char * nptr );
Long atol (const char * nptr );
Long long Atoll (const char * nptr );
Long long atoq (const char * nptr );

2. cstring mutual int Conversion

① Cstring to int
Converts a character to an integer. You can use atoi, _ atoi64, or atol.

② Int to cstring
To convert a number to a cstring variable, you can use the format function of cstring. For example
Cstring S;
Int I = 64;
S. Format ("% d", I)
The format function is very powerful and worth your research.

3. Convert cstring to char *

① Char * To cstring
Cstring strtest;
Char * charpoint;
Charpoint = "give string a value ";
Strtest = charpoint;
② Cstring to char *
Charpoint = strtest. getbuffer (strtest. getlength ());

Or

Direct (lpcstr) strtest

1. Convert cstring to string

String str1;

Cstring str2;

① Cstring to string

Str1 = (lpctstr) str2;

Or

String S (cstring. getbuffer ());
Releasebuffer () is required after getbuffer (). Otherwise, no space occupied by the buffer is released.

② String to cstring

Str2 = str1.c _ STR ();

C_str () is indeed better than data.
As mentioned in C ++ standard function library
There are three functions that can convert the content of a string to a character array and a C-string
1, data (), returns a string array without "/0"
2, c_str (), returns a string array with "/0"
3, copy ()

2, char * convert string

① Char to string
String S (char *);
You can only initialize it. It is best to use assign () unless it is initialized ().
② Convert string to char *
Char * P = string. c_str ();

 

This article from the csdn blog, reproduced please indicate the source: http://blog.csdn.net/primer_programer/archive/2007/12/26/1968061.aspx

 

This article from the csdn blog, reproduced please indicate the source: http://blog.csdn.net/primer_programer/archive/2007/12/26/1968065.aspx