Conversion Between the string type and common data types

1. String-> cstring

CString cs;string s("abc");cs.Format("%s",s.c_str());

2. String-> const char *

string s("abc");const char* c = s.c_str();

The c_str () function returns a regular pointer to a string in the C format. c ++ primer says, assigning the address of a const object to a normal, non-const object pointer will lead to compilation errors, but the non-const object address can be assigned to the pointer pointing to the const object. Therefore, the left operator must be a pointer to the const object.

3. String-> char *

 string source = "abcdefg"; int length = strlen(source.c_str()); char *s = new char[length+1]; memset(s,0,length+1); strcpy(s,source.c_str()); cout << s << endl; delete []s;

In this case, the memory is dynamically allocated.

4. String-> char []

string source = "abcdefg";char charArray[10];memset(charArray,0,10);strcpy(charArray,source.c_str());cout<<charArray<<endl;

5. String-> int

string source = "12";int a = atoi(source.c_str());cout << a <<endl;

6. Char buffer [row]-> string

char buffer[10] = {"abcdefg"};string source(buffer);cout << source << endl;

7. Char buffer [row] [line]-> string

char buffer[2][10] = {"abcd","asdf"};char buf[20];strcpy(buf,buffer[0]);strcat(buf,buffer[1]);string source(buf);cout << source << endl;

8. INT (float...)-> string

char buffer[20];int  i = 3445;   itoa( i, buffer, 10 );string s(buffer);cout<< s << endl;

char buffer[20];int  i = 3445;sprintf(buffer,"%d",i);string s(buffer);cout << s << endl;

 

// Stringstream () header file <sstream. h> int I = 3445; stringstream SS; SS <I; string S = ss. STR (); cout <S <Endl;

9. cstring-> string

Cstring STR; string buffer (STR); // or cstring STR; string STR (Str. getbuffer (); Str. releasebuffer ();

10. Char-> string

char c = 'a';string s(1,c);cout << s << endl;

11. char *-> string

char* ss = "abddas";string s(ss);cout << s << endl;

12. Char []-> string

char a[] = "adfadsf";string s(a);cout << s << endl;