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

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

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

Can you give me an example of using iterators 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 available in C++?

C++ provides several types of iterators:

1. Input Iterators - for reading data.
2. Output Iterators - for writing data.
3. Forward Iterators - can read and write data, and can be incremented.
4. Bidirectional Iterators - can be incremented and decremented.
5. Random Access Iterators - can access elements at any position.

How do I create a custom iterator?

To create a custom iterator, you need to define a class that implements the necessary iterator operations like operator++, operator*, and others. You also need to define the types of iterator you want to create, such as input or output.