Unlock the Power of Two Dimensional Array in C

Two dimensional array in C, often called matrices, are a fundamental data structure used to represent tabular data. Think of them as spreadsheets or grids, where you can access elements using row and column indices. Mastering two dimensional array is essential for tasks like image processing, matrix calculations, game boards, and more. In this comprehensive guide, we’ll delve into their declaration, initialization, usage, and practical examples.

Understanding Two Dimensional Array in C

A two-dimensional array in C is essentially an array of arrays. It’s a way to store data in a table-like format, with rows and columns. Each element is accessed using two indices:

• Row Index: Specifies the row of the element.
• Column Index: Specifies the column of the element.

Declaring Two Dimensional Array

You declare a two dimensional array in C using the following syntax:

data_type array_name[row_size][column_size];

For example, to declare a 2D array named matrix to store integers with 3 rows and 4 columns, you would write:

int matrix[3][4];

Initializing Two Dimensional Array

You can initialize a two-dimensional array at the time of declaration:

int matrix[3][4] = {
    {1, 2, 3, 4},
    {5, 6, 7, 8},
    {9, 10, 11, 12}
};

Alternatively, you can initialize it using nested loops:

int matrix[3][4];
for (int i = 0; i < 3; i++) {
    for (int j = 0; j < 4; j++) {
        matrix[i][j] = i * 4 + j; // Example initialization
    }
}

Accessing Elements in Two Dimensional Array

To access or modify individual elements, use the row and column indices:

int value = matrix[1][2];  // Accesses the element in the 2nd row, 3rd column
matrix[0][3] = 15;         // Modifies the element in the 1st row, 4th column

Practical Example: Storing Student Data

#include <stdio.h>

int main() {
    int students[5][2]; // Array for 5 students, storing roll no. and marks

    // Input data
    for (int i = 0; i < 5; i++) {
        printf("Enter roll no and marks for student %d: ", i + 1);
        scanf("%d %d", &students[i][0], &students[i][1]);
    }

    // Display data
    printf("\nRoll No.\tMarks\n");
    for (int i = 0; i < 5; i++) {
        printf("%d\t%d\n", students[i][0], students[i][1]);
    }

    return 0;
}

FAQs: Two-Dimensional Arrays in C