C++ STL Introduction – Superpower Tools for C++ Coders

The Standard Template Library (STL) is like a toolbox in C++ — packed with ready-to-use containers (like lists and maps), algorithms (like sorting), and iterators (for moving through data).

Instead of writing your own code to store and manage data, STL gives you super-fast, built-in solutions that work like magic!

STL Components

Containers: Hold your data (like vector, list, map)
Algorithms: Work on data (like sort(), find(), count())
Iterators: Smart pointers to walk through containers

Example: Using a Vector

#include <iostream>

#include <vector>

using namespace std;

int main() {

vector<int> nums = {10, 20, 30};

nums.push_back(40); // Add another item

for (int n : nums) {

cout << n << " ";

}

return 0;

}

#include <iostream> #include <vector> using namespace std; int main() { vector<int> nums = {10, 20, 30}; nums.push_back(40); // Add another item for (int n : nums) { cout << n << " "; } return 0; }

#include <iostream>
#include <vector>
using namespace std;

int main() {
    vector<int> nums = {10, 20, 30};

    nums.push_back(40); // Add another item

    for (int n : nums) {
        cout << n << " ";
    }

    return 0;
}

Try It Now

Why Use STL?

Saves time – no need to build everything yourself
Well-tested and efficient
Easy to reuse and flexible for many tasks

Fun Fact

The STL is part of the C++ Standard Library, which means it’s already available — no extra setup required. Just include the headers!

Summary

STL is a powerful library of containers, algorithms, and iterators.
It makes your code faster, shorter, and smarter.
Next up: Let’s start using STL containers like vector and list!