C++ Standard Libraries

C++ provides a rich collection of standard libraries that offer a wide range of functionalities to simplify and accelerate development. These libraries contain pre-defined classes and functions that can be utilized to perform common tasks, such as input/output operations, mathematical computations, string manipulations, and more. In this article, we will introduce you to some of the most commonly used C++ standard libraries with examples.

1. iostream

The iostream library is essential for input/output operations. It provides classes, such as iostream, istream, and ostream, to handle input from the user and output to the console. Here's an example:

#include <iostream>

int main() {
    int num;
    std::cout << "Enter a number: ";
    std::cin >> num;
    std::cout << "You entered: " << num << std::endl;

    return 0;
}

In the above code, we use std::cin to read input from the user and std::cout to display output on the console.

2. cmath

The cmath library provides mathematical functions and constants. It includes functions for basic arithmetic operations, trigonometry, logarithms, and more. Here's an example:

#include <iostream>
#include <cmath>

int main() {
    double radius = 2.5;
    double area = M_PI * pow(radius, 2);

    std::cout << "Area of the circle: " << area << std::endl;

    return 0;
}

In the above code, we calculate the area of a circle using the M_PI constant from the cmath library and the pow function to raise the radius to the power of 2.

3. string

The string library provides classes and functions to handle strings in C++. It offers convenient ways to create, manipulate, and concatenate strings. Here's an example:

#include <iostream>
#include <string>

int main() {
    std::string name = "John";
    std::string greeting = "Hello, " + name;

    std::cout << greeting << std::endl;

    return 0;
}

In the above code, we use the std::string class to create strings and the concatenation operator (+) to join strings together.

4. vector

The vector library provides a dynamic array implementation in C++. It allows you to create resizable arrays and provides functions for adding, removing, and accessing elements. Here's an example:

#include <iostream>
#include <vector>

int main() {
    std::vector<int> numbers;

    numbers.push_back(1);
    numbers.push_back(2);
    numbers.push_back(3);

    for (int num : numbers) {
        std::cout << num << " ";
    }
    std::cout << std::endl;

    return 0;
}

In the above code, we use the std::vector class to create a dynamic array of integers. We add elements to the vector using push_back() and then iterate over the vector to print the elements.

These are just a few examples of the many standard libraries available in C++. By leveraging these libraries, you can save time and effort in implementing common functionalities and focus on solving the core problems in your programs.

Explore the C++ standard libraries documentation to discover more features and functionalities. Experiment with different libraries and their functions to enhance your programming skills and efficiency.