What are C++ iterators and how do they work?

What are C++ iterators and how do they work?

C++ iterators are objects that allow you to traverse through the elements of a container, like arrays or vectors, without exposing the underlying structure. They provide a way to access elements sequentially.

Can you give me an example of using an iterator with a vector?

Sure! Here's a simple example:

#include <iostream>
#include <vector>

int main() {
    std::vector<int> vec = {1, 2, 3, 4, 5};
    for (std::vector<int>::iterator it = vec.begin(); it != vec.end(); ++it) {
        std::cout << *it << ' ';
    }
    return 0;
}

This code uses an iterator to print each element in the vector.

What are the different types of iterators in C++?

C++ has several types of iterators:

1. Input Iterators - Read elements from a container.
2. Output Iterators - Write elements to a container.
3. Forward Iterators - Read and write elements, can be incremented.
4. Bidirectional Iterators - Can be incremented and decremented.
5. Random Access Iterators - Can access elements at any position in constant time.

How do iterators compare to pointers in C++?

Iterators and pointers both provide a way to access elements in a container, but iterators are more abstract. They can work with different types of containers, while pointers are specific to arrays. Iterators also provide additional functionality, like the ability to work with different types of data structures.