C ++ int, Char, String, cstring type conversion (Summary)

# Include <string>// When using the string class of the C ++ standard library

Using namespace STD;// Same as above

# Include <sstream> 

# Include <iostream>

#include // it is best to directly convert the string and INT types.

// you can easily write a conversion function by yourself, function definition reference

String getstring (const int N)

{

STD: stringstream newstr;
newstr return newstr. STR ();

}

////////// The following is reproduced from the http://successfulfortune.com/icode? P = 4

String to cstring
Cstring. Format ("% s", String. c_str ());

Convert Char to cstring
Cstring. Format ("% s", char *);

Char to string
String S (char *);

String to char *
Char * P = string. c_str ();

cstring to string
string S (cstring. getbuffer ();

1, string-> cstring
cstring. format ("% s", String. c_str ();
using c_str () is indeed better than using data.
2, char-> string
string S (char *);
only Initialization is supported. It is best to use assign () instead of initialization ().
3, cstring-> string
string S (cstring. getbuffer ();
after getbuffer (), it must be releasebuffer (); otherwise, no space occupied by the buffer is released.

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 ()

---------------------

Conversion between cstring, Int, char *, and char [100 --

Conversion between cstring, Int, char *, and char [100 --

Cstring mutual int Conversion

converts a character to an integer. You can use atoi, _ atoi64, or atol.
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 studying.

void cstrdlg: onbutton1 ()
{< br> // todo: add your control notification handler code here
cstring
SS = "1212.12";
int temp = atoi (SS);
cstring AA;
AA. format ("% d", temp);
afxmessagebox ("VaR is" + AA);
}

Sart. Format ("% s", Buf );

Convert cstring to char *

// char * To cstring
cstring strtest;
char * charpoint;
charpoint = "give string a value";
strtest = charpoint;

/// Cstring to char *
Charpoint = strtest. getbuffer (strtest. getlength ());

There is no string in Standard C, char * = char [] = string

You can use the cstring. Format ("% s", char *) method to convert char * To cstring. To convert cstring to char *, use the operator (lpcstr) cstring.

Cstring conversion char [100]

Char A [100];
Cstring STR ("aaaaaa ");
Strncpy (A, (lpctstr) STR, sizeof ());

 

 

Instance:

# Include <iostream>

# Include <stdarg. h>

# Include <stdio. h>

Using namespace STD;

String consiststr (const char * format,...) {If (! Format) return false; va_list AP; char szquery [4096]; va_start (AP, format); int res = vsnprintf (szquery, 4096, format, AP); va_end (AP ); if (RES =-1) {return "";} return string (szquery );

}

Cout <consiststr ("AAAA % d, % s", 12, "FS") <Endl;