字符串名称，作为指向第一个字符的指针

Question

Given

string name="avinash";  
cout<<&name;  

If name is a pointer to a then how are we using address on a pointer?

Answer 1

name is not a pointer, it's the std::string itself. So &name is the address of that string, which means that this code will print out a number.

Even if it were a pointer, using operator & on it would be perfectly legal: it would return the address of the pointer variable in memory (another, different, number).

If you want a pointer to the first character inside name , then use name.c_str() to get a C-style null-terminated string (which is actually a pointer to the first character of a string), or name.data() which returns a pointer to the string but doesn't guarantee that it will be null-terminated.

Answer 2

name is not a pointer, name is a std::string object. &name , which is a pointer, is the address of that object.

Answer 3

1. name is not a pointer, it is an object of type std::string . &name gives you the address of that object.
2. To obtain a (const-)pointer to the first character of the string, use name.c_str() .

3. Pointers have addresses too!

    int i = 5; int *j = &i; int **k = &j; 

   This is useful if you want to pass a pointer to a function that has to manipulate that pointer (for instance by allocating memory):

    void allocate_string(std::string **foo) { *foo = new std::string(); } 

Answer 4

Hi string class have c_str() method. Use const char* ptr = name.c_str();