Append a value to end of a std::vector in C++

This post will discuss how to append a value to the end of a vector in C++.

1. Using `std::vector::push_back`

The standard solution to add an element at the end of the vector is using the std::vector::push_back member function. A typical invocation for this method would look like this:

#include <iostream>

#include <vector>

int main()

{

std::vector<int> values = {3, 4, 6, 7};

int item = 8;

values.push_back(item);

for (int &i: values) {

std::cout << i << ' ';

}

return 0;

}

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Output:

3 4 6 7 8

2. Using `std::vector::insert`

Alternatively, we can use the std::vector::insert member function, which inserts the specified element before the specified position. It can be used as follows:

#include <iostream>

#include <vector>

int main()

{

std::vector<int> values = {3, 4, 6, 7};

int item = 8;

values.insert(values.end(), item);

for (int &i: values) {

std::cout << i << ' ';

}

return 0;

}

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Output:

3 4 6 7 8

The std::vector::insert function allows inserting the multiple elements before the specified position, as shown below:

#include <iostream>

#include <vector>

int main()

{

std::vector<int> values = {3, 4, 6, 7};

std::vector<int> items = {8, 9};

values.insert(values.end(), items.begin(), items.end());

for (int &i: values) {

std::cout << i << ' ';

}

return 0;

}

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Output:

3 4 6 7 8 9

3. Using `std::copy`

Another option is to use the std::copy algorithm to append values to the end of a vector, as shown below. Note that std::back_inserter is used for allocating space for the new element.

#include <iostream>

#include <vector>

#include <algorithm>

int main()

{

std::vector<int> values = {3, 4, 6, 7};

std::vector<int> items = {8, 9};

std::copy(items.begin(), items.end(), std::back_inserter(values));

for (int &i: values) {

std::cout << i << ' ';

}

return 0;

}

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Output:

3 4 6 7 8 9

That’s all about appending a value to the end of a vector in C++.

Append a value to end of a std::vector in C++

1. Using std::vector::push_back

2. Using std::vector::insert

3. Using std::copy

Share this:

1. Using `std::vector::push_back`

2. Using `std::vector::insert`

3. Using `std::copy`