Creating a 2D Vector of Structs in C

In this article, we will explore how to create a 2D vector of structs in C using the Standard Template Library (STL) from the C language. We'll walk through a step-by-step process with a detailed example to illustrate the process.

Introduction to C and C

C is a general-purpose programming language that extends the capabilities of the C programming language. It supports features like object-oriented programming, generic programming, and low-level memory manipulation. Using C alongside C makes it easier to develop complex software systems with high performance and reliability.

Step-by-Step Guide

Step 1: Define Your Struct

First, we need to define the struct that we want to store in the 2D vector. Let's consider a simple example where we define a Point struct that holds two integer values, x and y representing coordinates.

struct Point {    int x;    int y;};

Step 2: Create a 2D Vector of the Struct

Next, we will create a 2D vector of the defined Point struct. In C , we use the std::vector from the STL to achieve this. The 2D vector will consist of a vector of vectors, where each inner vector represents a row in the 2D array.

#include iostream#include vector

We declare the 2D vector points with 3 rows and 4 columns, and each element will be of type Point.

std::vectorstd::vectorPoint points(3, std::vectorPoint(4));

Step 3: Populate the Vector

We populate the 2D vector with some example data using a nested loop. In this example, we assign the x and y values based on their respective row and column indices.

for (int i  0; i  3; i  ) {    for (int j  0; j  points[i].size(); j  ) {        points[i][j]  {i, j}; // Assign x and y based on their indices    }}

Step 4: Print the Vector

Finally, we print the contents of the 2D vector using another nested loop. This will display the coordinates of each Point in the vector.

for (const auto row : points) {    for (const auto point : row) {        std::cout  "('"  point.x  "' , '"  point.y  "') ";    }    std::cout  std::endl;}

Compilation and Execution

To compile and run the code, you can use a C compiler like g . Save the code in a file named main.cpp and run the following commands in your terminal:

g   main.cpp -o main./main

This will output the coordinates of the points in the 2D vector.

Enhanced Example: Creating a 2D Vector of Floating Point Structs

Here's a more complex example where we define a vec2D struct that can hold two floating-point numbers. We also create some initial structs and demonstrate how to populate and print them.

struct vec2D {    float a, X, a, Y;};vec2D a  {0.0, 1.0};vec2D origo  {0.0, 0.0};