Vector pointer

[thephysicsguru]

I'm looking for some assistance in understanding a pointer to a vector. Suppose I have the following:

std::vector<string> string_vector;

This statement instantiates a vector of type string with zero elements.

Now, if I have:

std::vector<string> * p_string_vector;

Does this mean p_string_vector is essentially a vector of pointers (contains addresses of the elements of the vector)?

How would I dereference each element of p_string_vector to get the string (not the address)?

Thanks in advance!

L.

[LB]

It is a pointer to a vector of strings. p_string_vector itself is a pointer, and when you dereference it you get the vector of strings.

This is a vector of pointers, which is different:
std::vector<std::string*> vector_of_string_pointers;

You would access the elements the same way, except that since they are pointers you probably want to get what they are pointing to by dereferencing them.

[thephysicsguru]

Great. Now that I think about it, this makes sense. It follows the same format as standard pointers:

int i = 0; // holds the value 0
int * i = &i;  // holds the address of i 

How does one deal with iterations of std::vector<string>* p_string_vector ?

For example:

//snippet of code
std:vector<string> string_vector;  
string_vector.push_back ("Hello ");
string_vector.push_back ("World!");

std:vector<string> * p_string_vector = &string_vector;  // i would like to iterate across this and cout the value

std::vector<string>::iterator it;  // instantiate the iterator  (is there a special iterator for pointers?)

for (it=p_string_vector.begin(); it!=p_string_vector.end(); ++it)
{
std::cout << *it << std::endl;
}

[jsmith]

begin() and end() are member functions of std::vector<>. Since you have a pointer to one of those, you use pointer syntax to call the member functions. Eg., p_string_vector->begin().

[thephysicsguru]

Man, you guys are awesome. By far, the best resource I've found on the web.

Thanks again!!