Conversion of various characters, string types

Itoa function: Convert an integer to a string
Usage: char *itoa (int value, char *string, int radix);
Explanation: ITOA is an abbreviation for the English Integer to array (converting int integer to a string and storing the value in the array string).
Parameters:
Value: the integer to convert.
Radix: Is the meaning of the cardinality, that is, the value is converted to the number of radix, the range is between 2-36, for example, 10 means 10, 16 means 16 binary.
* String: The string to be saved after the conversion.
return value:
char *: Points to the generated string, with *string.

Note: The function's header file is "Stdlib.h"

#include <stdlib.h>

#include <stdio.h>

int main ()

{

int number = 123456;

Char string[25];

Itoa (number, string, 10);

printf ("integer =%d string =%s\n", number, string);

return 0;

}

Atoi C language Library function name: atoi
Function: Converts a string to an integer number
Function Description: Atoi () scans the parameter nptr string, detects the first number or positive sign when the type conversion is started, and then detects a non-numeric or terminator when the conversion is stopped, returning an integer number.
Prototype: int atoi (const char *nptr);
Header files to use: #include <stdlib.h>
program Example:
1)
#include <stdlib.h>
#include <stdio.h>
int main (void)
{
int n;
Char *str = "12345.67";
n = atoi (str);
printf ("string =%s integer =%d\n", str, n);
return 0;
}
Execution results

string = 12345.67 integer = 12345

String Turn CString
Cstring.format ("%s", String.c_str ());

Char Turn CString
Cstring.format ("%s", char*);

Char to String
string S (char *);

String to char *
Char *p = STRING.C_STR ();

CString Turn string
String s (Cstring.getbuffer ());

1,string-CString
Cstring.format ("%s", String.c_str ());
Using C_str () is really better than data ().
2,char, String
string S (char *);
You can initialize only, preferably in a place that is not initialized or with assign ().
3,cstring, String
String s (Cstring.getbuffer ());
GetBuffer () must be releasebuffer (), otherwise the space occupied by the buffer will not be released.


In the C + + standard function library.
There are three functions to convert the contents of a string to a character array and c-string
1.data (), returns an array of strings without "\"
2,C_STR (), returns an array of strings with "\"
3,copy ()

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Conversion between CString and int, char*, char[100]--


Conversion between CString and int, char*, char[100]--



CString Mutual Transfer int

To convert a character to an integer, you can use Atoi, _atoi64, or ATOL.
Instead of converting a number to a CString variable, you can use the CString format function. Such as
CString s;
int i = 64;
S.format ("%d", i)
The Format function is very powerful and deserves your research.

void Cstrdlg::onbutton1 ()
{
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);

CString Mutual Transfer char*

char * to CString
CString strtest;
char * CHARPOINT;
Charpoint= "Give string a value";
Strtest=charpoint;


CString to char *
Charpoint=strtest. GetBuffer (strtest. GetLength ());

No String,char *==char in standard C []==string

You can use the Cstring.format ("%s", char *) method to turn char * into CString. To turn CString into char *, use the operator (LPCSTR) to CString.


CString conversion char[100]

Char a[100];
CString Str ("aaaaaa");
strncpy (A, (LPCTSTR) str,sizeof (a));

Convert CString type to int
To convert a character to an integer, you can use Atoi, _atoi64, or ATOL.

CString AAA = "16";
int int_chage = Atoi ((LPCSTR) AAA);


Instead of converting a number to a CString variable, you can use the CString format function. Such as
CString s;
int i = 64;
S.format ("%d", i)
The Format function is very powerful and deserves your research.
If you are using a char array, you can also use the sprintf function.

CString ss= "1212.12";
int Temp=atoi (ss);
CString AA;
Aa. Format ("%d", temp);


Numbers--strings in addition to using Cstring::format, there are FORMATV, sprintf and itoa that do not need AFX

#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);

String AA ("AAA"); Char *c=aa.c_str (); Cannot convert from ' const char * ' to ' char * ' const char *C=AA.C_STR ();

STRING.C_STR () can only be converted to a const char *,
To turn to char * write this:

String Mngname;
Char t[200]; memset (t,0,200); strcpy (T,mngname.c_str ());

Conversion of various characters, string types