Conversion of String, char *, char[] in C + +

The first time someone asked me this question, but I do not have a clue, directly said no. Now from the Internet to find some information, looked at, know something.

One, the string to turn char*.

There are three main ways to convert str to char* type: data (); C_str (); Copy ();

1.data () method, such as:

1 string " Hello " ; 2 char* p = str.data ();

2.c_str () method, such as:

1 string str="World"; 2 char *p = Str.c_str ();

3.copy () method, such as:

1 string str="hmmm"; 2 Char p[]; 3 5 0); // here 5 means to copy a few characters, 0 for the location of the copy 4 * (p+5) ="+"; // Note the manual plus Terminator!!! 

Second, char * turn string.

You can assign values directly.

1 string s; 2 Char " Hello "; // Direct Assignment 3 s = p;

One thing to note here is that when the string type variable s is declared, it is used with printf ("%s", s); The error occurs because "%s" requires the first address of the object that follows. But string is not such a type. So it must be wrong.

Iii. string Transfer char[]

This is because we know the length of the string, can be obtained according to length () function, and can be directly accessed according to subscript, so we can assign a value with a loop.

1     stringPP ="Dagah";2     Charp[8];3     inti;4      for(i=0; I<pp.length (); i++)5P[i] =Pp[i];6P[i] =' /';7printf"%s\n", p);8cout<<p;

Iv. char[] Turn string

You can assign values directly here.

Conversion of String, char *, char[] in C + +