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 <stdlib. h> // it is best to directly convert string and INT types to include,

// Because it is easier to write a conversion function, the function definition is as follows:

String getstring (const int N)

{

STD: stringstream newstr;

Newstr <N;

Return newstr. STR ();

}

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 ());

It is indeed better to use c_str () than data ().

2char-> string

String (char *)

Only Initialization is allowed. It is best to use assign () instead of initialization ();

3, cstring-> string

String S (cstring. getbuffer ());

Releasebuffer () is required after getbuffer (); 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 the c_string of the character array.

1. Data (), returns a string array without '\ 0'

2. c_str (), returns a string array with '\ 0'

3. Copy ()

 

Conversion between cstring and INT, char *, char [100]

Conversion between cstring and INT, char *, 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 worthy of research.

Void cstrdlg: onbutton1 ()

{

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 *

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. You can use the operator (lpcstr) cstring.

Cstring conversion char [100]

Char A [100];

Cstring STR ("AAAAA ");

Strncpy (A, (lpcstr) STR, sizeof ());

 

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