String to char *

String is one of the c ++ standard libraries, which encapsulates string operations.
There are three methods to convert string to char:
1. data
For example:
String str = "abc ";
Char * p = str. data ();
2. c_str
For example, string str = "gdfd ";
Char * p = str. c_str ();
3. copy
For example
String str = "hello ";
Char p [40];
Str. copy (p, 5, 0); // here, 5 represents the number of characters to be copied, and 0 represents the copy position.
* (P + 5) = '\ 0'; // You must manually add the Terminator.
Cout <p;

Example program:

# Include <iostream>
# Include <string>
Using namespace std;

Int main ()
{
String line;
Getline (cin, line );
Char str [20];
Int size = line. size ();
Line. copy (str, line. size (), 0 );
// Char str [20] = "liuyanbo ";
Char upper [20];
For (int I = 0; I <size; ++ I)
{
// Cout <static_cast <char> (toupper (str [I]);
Upper [I] = static_cast <char> (toupper (str [I]);
}
Upper [I] = '\ 0 ';
Cout <upper <endl;
Return 0;
}