How do I access elements in a 2D vector in C++11?

How do I access elements in a 2D vector in C++11?

You can access elements in a 2D vector using the syntax vector[row][column]. For example, vec[1][2] accesses the element in the second row and third column.

What if I want to iterate through all the elements?

You can use nested loops to iterate through all elements. For example:

for (int i = 0; i < vec.size(); ++i) {
    for (int j = 0; j < vec[i].size(); ++j) {
        cout << vec[i][j] << " ";
    }
}

Can I use range-based for loops with a 2D vector?

Yes, you can! Here's how:

for (const auto& row : vec) {
    for (const auto& elem : row) {
        cout << elem << " ";
    }
}

What happens if I try to access an out-of-bounds index?

Accessing an out-of-bounds index will lead to undefined behavior. It's important to check the size of the vector before accessing elements.