C++ - Vectors Part 1: Introduction to Vectors

Vectors are part of the std namespace and offer dynamic resizing capabilities, unlike static arrays. To use vectors, include the <vector> header.

Examples and Explanation

Declaring and Initializing Vectors

#include <iostream>

#include <vector>

int main() {

    std::vector<int> vec; // Empty vector

    std::vector<int> vec2 = {1, 2, 3}; // Initialized with values

    std::vector<int> vec3(5, 10); // 5 elements, each initialized to 10

    return 0;

}

Explanation: Vectors can be initialized empty, with specific values, or with a specified size and default value.

Accessing Elements

vec2[0] = 5;

std::cout << vec2[0]; // Output: 5

Explanation: Elements can be accessed using the [] operator or the .at() method, which provides bounds checking.

Adding Elements

vec.push_back(4); // Add 4 to the end of the vector

Explanation: The push_back() method appends elements to the vector, automatically resizing it.