Convert a list to a vector in C++

In this article, we will discuss how to convert a list to a vector in C++.

Table Of Contents

Method 1: Using Range based constructor of vector

Pass the start, and end iterators of a list, to the vector constructor, while creating the vector object. It will create a vector object populated with the list contents. Let’s see an example,

#include <iostream>
#include <vector>
#include <list>

template <typename T>
void display(std::vector<T> vectorObj)
{
    // Iterate over all elements of vector
    for(auto& elem : vectorObj)
    {
        std::cout<<elem << ", ";
    }
    std::cout<<std::endl;
}


int main()
{

    std::list<int> listOfNumbers = {11, 12, 13, 14, 15, 16};

    // Create a vector from list elements
    // using range constructor
    std::vector<int> vectorOfnumbers(
                        listOfNumbers.begin(),
                        listOfNumbers.end());

    display(vectorOfnumbers);

    return 0;
}

Output:

11, 12, 13, 14, 15, 16, 

It converted the list to a vector.

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Method 2: using vector::push_back()

Iterate over all the characters of a list using a range based for loop. During iteration, add each character to the vector using the member function push_back(). It accepts an element as an argument, and adds that to the end of vector. Let’s see an example,

#include <iostream>
#include <vector>
#include <list>

template <typename T>
void display(std::vector<T> vectorObj)
{
    // Iterate over all elements of vector
    for(auto& elem : vectorObj)
    {
        std::cout<<elem << ", ";
    }
    std::cout<<std::endl;
}

int main()
{
    std::list<int> listOfNumbers = {11, 12, 13, 14, 15, 16};

    std::vector<int> vectorOfnumbers;

    // Iterate over all characters of list
    for (auto& elem : listOfNumbers)
    {
        // Add each character to vector
        vectorOfnumbers.push_back(elem);
    }

    display(vectorOfnumbers);

    return 0;
}

Output:

11, 12, 13, 14, 15, 16, 

It converted the list to a vector.

Method 3: using STL Algorithm copy()

Pass two iterators pointing to the first, and one past the last element of list to the copy() function, as a range. Also, pass a back_insert_iterator of vector object to the copy() function. It will copy all the elements of list, to the vector. Let’s see an example,

#include <iostream>
#include <vector>
#include <list>
#include <algorithm>

template <typename T>
void display(std::vector<T> vectorObj)
{
    // Iterate over all elements of vector
    for(auto& elem : vectorObj)
    {
        std::cout<<elem << ", ";
    }
    std::cout<<std::endl;
}

int main()
{
    std::list<int> listOfNumbers = {11, 12, 13, 14, 15, 16};

    std::vector<int> vectorOfnumbers;

    // copy all elements of list to vector
    std::copy(
        listOfNumbers.begin(),
        listOfNumbers.end(),
        std::back_inserter(vectorOfnumbers));

    display(vectorOfnumbers);

    return 0;
}

Output:

11, 12, 13, 14, 15, 16, 

It converted the list to a vector.

Summary

We learned how to convert a list to a vector in C++.

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Thanks for reading.

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