C 2D Arrays

📚 C 2D Arrays – Working with Multidimensional Arrays

A 2D array in C is an array of arrays. It is a collection of data elements organized in a grid-like structure, which can be thought of as a table with rows and columns. 2D arrays are commonly used to represent matrices or tables of data.

🔹 Declaring and Initializing a 2D Array

To declare a 2D array, you specify the number of rows and columns. The declaration looks similar to that of a 1D array, but with two dimensions.

📝 Example 1: Declaring a 2D Array

Here’s an example of how to declare a 2D array of integers:

#include <stdio.h>

int main() {
    int matrix[2][3]; // Declaring a 2D array with 2 rows and 3 columns
    matrix[0][0] = 1; // Assigning value to the first element
    matrix[0][1] = 2; // Assigning value to the second element
    matrix[0][2] = 3; // Assigning value to the third element
    printf("Element at row 1, column 1: %d\n", matrix[0][0]);
    return 0;
}
  

🔹 Initializing a 2D Array

You can initialize a 2D array at the time of declaration by specifying values for each element. You can also omit the size of one dimension, and the compiler will infer it from the initialization.

📝 Example 2: Initializing a 2D Array

Here’s an example of initializing a 2D array:

#include <stdio.h>

int main() {
    int matrix[2][3] = {{1, 2, 3}, {4, 5, 6}}; // Initializing a 2D array
    
    printf("Element at row 1, column 1: %d\n", matrix[0][0]);
    printf("Element at row 2, column 3: %d\n", matrix[1][2]);
    
    return 0;
}
  

🔹 Accessing Elements of a 2D Array

To access an element in a 2D array, you use two indices: one for the row and one for the column. The first index refers to the row, and the second refers to the column.

📝 Example 3: Accessing Elements of a 2D Array

In this example, we access each element of the 2D array and print it:

#include <stdio.h>

int main() {
    int matrix[2][3] = {{1, 2, 3}, {4, 5, 6}};
    
    // Accessing and printing each element using nested loops
    for (int i = 0; i < 2; i++) {
        for (int j = 0; j < 3; j++) {
            printf("Element at row %d, column %d: %d\n", i + 1, j + 1, matrix[i][j]);
        }
    }
    
    return 0;
}
  

🎯 Key Points about 2D Arrays

• A 2D array is an array of arrays, with two dimensions: rows and columns.
• Elements in a 2D array are accessed using two indices: one for the row and one for the column.
• The size of a 2D array can be defined during declaration, or it can be inferred if initialized.
• 2D arrays are commonly used to represent tables, grids, or matrices.

💡 Practice Challenge

Try modifying the number of rows and columns in the 2D array. Add loops to traverse and print the elements in a different way. Experiment with storing different types of data (e.g., floating-point numbers) in a 2D array!