Dynamic Array in C++

The C++ dynamic array is typically implemented using the std::vector container from the Standard Template Library (STL). A dynamic array, often referred to as a “vector,” allows you to create an array whose size can change dynamically during runtime. Here’s how you can use std::vector in C++:

#include <iostream>
#include <vector>

int main() {
    // Declare an empty dynamic array (vector)
    std::vector<int> dynamicArray;

    // Add elements to the dynamic array
    dynamicArray.push_back(1);
    dynamicArray.push_back(2);
    dynamicArray.push_back(3);

    // Access elements in the dynamic array
    std::cout << "Elements in the dynamic array:" << std::endl;
    for (int i = 0; i < dynamicArray.size(); ++i) {
        std::cout << dynamicArray[i] << " ";
    }
    std::cout << std::endl;

    // Modify elements in the dynamic array
    dynamicArray[1] = 4;

    // Remove elements from the dynamic array
    dynamicArray.pop_back();

    // Size of the dynamic array
    std::cout << "Size of the dynamic array: " << dynamicArray.size() << std::endl;

    // Clear all elements in the dynamic array
    dynamicArray.clear();

    // Check if the dynamic array is empty
    if (dynamicArray.empty()) {
        std::cout << "The dynamic array is empty." << std::endl;
    } else {
        std::cout << "The dynamic array is not empty." << std::endl;
    }

    return 0;
}

In this example:

1. We include the necessary headers (<iostream> and <vector>) for using std::vector.
2. We declare an empty dynamic array (vector) called dynamicArray.
3. We use the push_back() method to add elements to the end of the dynamic array.
4. We access elements using the index notation, just like a regular array.
5. We modify elements using the same index notation.
6. We use the pop_back() method to remove the last element from the dynamic array.
7. We use the size() method to determine the size of the dynamic array.
8. We use the clear() method to remove all elements from the dynamic array.
9. We use the empty() method to check if the dynamic array is empty.

std::vector takes care of dynamically resizing the array as needed, so you don’t have to worry about memory management or manual resizing. It provides a convenient and efficient way to work with dynamic arrays in C++.