What are C++ Vectors?

In C++, a vector is a sequence container that encapsulates dynamic arrays. Unlike static arrays, which have a fixed size, vectors can grow or shrink dynamically as elements are added or removed. This makes vectors a more flexible and convenient choice for storing collections of data.

Creating a Vector

To use vectors in C++, you need to include the <vector> header file. Once included, you can create a vector using the following syntax:

#include <vector>

// Create an empty vector
std::vector<int> numbers;

// Create a vector with initial values
std::vector<int> numbers = {1, 2, 3, 4, 5};

In the above example, we create two vectors: numbers and numbers with initial values. The angle brackets specify the type of elements the vector will store, in this case, int.

Accessing and Modifying Elements

You can access elements in a vector using the indexing operator ([]) or the at() method. Here’s an example:

std::vector<int> numbers = {1, 2, 3, 4, 5};

// Access elements
int firstElement = numbers[0];
int secondElement = numbers.at(1);

// Modify elements
numbers[2] = 10;

In the above code snippet, we access and modify elements in the numbers vector. The first element is accessed using the indexing operator, the second element is accessed using the at() method, and the third element is modified using the indexing operator.

Adding and Removing Elements

Adding elements to a vector is done using the push_back() method, while removing elements can be achieved using the pop_back() method or the erase() method. Here’s an example:

std::vector<int> numbers;

// Add elements
numbers.push_back(1);
numbers.push_back(2);
numbers.push_back(3);

// Remove elements
numbers.pop_back();
numbers.erase(numbers.begin() + 1);

In the above code snippet, we add elements to the numbers vector using the push_back() method. We then remove the last element using the pop_back() method and remove the second element using the erase() method.

Conclusion

C++ vectors are a valuable tool for managing collections of data. They allow for dynamic resizing and provide convenient methods for accessing, modifying, adding, and removing elements. By incorporating vectors into your C++ programs, you can handle dynamic arrays with ease and efficiency.

#cplusplus #vectors