What does -> mean in C++? [duplicate]

Question

Possible Duplicates:
What is the difference between the dot (.) operator and -> in C++?
What is the arrow operator (->) synonym for in C++?

The header says it all.

What does -> mean in C++?

Answer 1

It's to access a member function or member variable of an object through a pointer, as opposed to a regular variable or reference.

For example: with a regular variable or reference, you use the . operator to access member functions or member variables.

std::string s = "abc"; std::cout << s.length() << std::endl; 

But if you're working with a pointer, you need to use the -> operator:

std::string* s = new std::string("abc"); std::cout << s->length() << std::endl; 

It can also be overloaded to perform a specific function for a certain object type. Smart pointers like shared_ptr and unique_ptr, as well as STL container iterators, overload this operator to mimic native pointer semantics.

For example:

std::map<int, int>::iterator it = mymap.begin(), end = mymap.end(); for (; it != end; ++it)     std::cout << it->first << std::endl; 

Answer 2

a->b means (*a).b.

If a is a pointer, a->b is the member b of which a points to.

a can also be a pointer like object (like a vector<bool>'s stub) override the operators.

(if you don't know what a pointer is, you have another question)