Vector push_back() in C++ STL (original) (raw)

Last Updated : 27 Dec, 2024

In C++, the **vector push_back() is a built-in method used to add a new element at the end of the vector. It automatically resizes the vector if there is not enough space to accommodate the new element.

Let’s take a look at an example that illustrates the vector push_back() method:

C++ `

#include <bits/stdc++.h> using namespace std;

int main() { vector v = {1, 4, 6};

// Add an element at the end of the vector
v.push_back(9);

for (int i : v)
    cout << i << " ";
return 0;

}

`

This article covers the syntax, usage, and common examples of the vector push_back() method in C++:

Table of Content

• Syntax of Vector push_back()
• Examples of vector push_back()
  • Initialize an Empty Vector One by One
  • Add Elements Vector of Strings at the End

**Syntax of Vector push_back()

The vector push_back() is a member method of the std::vector class defined inside the ****** header file.

v.**push_back(val);

**Parameters:

• **val: Element to be added to the vector at the end.

**Return Value:

• This function does not return any value.

Examples of vector push_back()

The following examples demonstrate the use of the vector push_back() function for different purposes:

Initialize an Empty Vector One by One

C++ `

#include <bits/stdc++.h> using namespace std;

int main() { vector v;

// Add elements to the vector
v.push_back(3);
v.push_back(7);
v.push_back(9);

for (int i : v)
    cout << i << " ";
return 0;

}

`

Add Elements Vector of Strings at the End

C++ `

#include <bits/stdc++.h> using namespace std;

int main() { vector v = {"Hello", "Geeks"};

// Add string to the vector
v.push_back("Welcome");

for (string s: v) 
    cout << s << " ";
return 0;

}

`

Output

Hello Geeks Welcome