LANGUAGE » CPP

Array

Last updated:
Reference:cplusplus.com

Vectors ​

Creating vectors and optionally debugging (by including fmt/ranges.h):

cpp
#include <vector>

int main()
{
    // Initialization
    std::vector<int> numbers;
    numbers.push_back(2);
    numbers.push_back(3);
    numbers.push_back(5);
    std::vector<char> letters = {'a', 'c', 'f'};

    // Debug
    fmt::print("{}\n", numbers);
    fmt::print("{}\n", letters);
    return 0;
}

TIP

Use .reserve(size) to request a custom capacity (good to avoid multiple reallocations).

Manual dynamic array ​

Use the new keyword to create a new array dinamically. Don't forget to delete it.

cpp
#include <fmt/ranges.h>

int main()
{
    // Initialization
    size_t size = 3;
    int* numbers = new int[size];
    numbers[1] = 99;

    // Debug
    fmt::print("[{}]\n", fmt::join(numbers, numbers + size, ", "));
    delete[] numbers;
    return 0;
}

It may be a good idea to use a Smart Pointer. In this case there is no need to delete it.

Debugging its contents is a bit more verbose (if not using c++20 features).

cpp
#include <fmt/base.h>
#include <memory>

int main()
{
    // Initialization
    size_t size = 3;
    auto numbers = std::make_unique<int[]>(size);
    numbers[1] = 99;

    // Debug
    fmt::print("[");
    for (size_t i = 0; i < size - 1; ++i) {
        fmt::print("{}, ", numbers[i]);
    }
    fmt::print("{}]\n", numbers[size - 1]);
    return 0;
}