> ## Documentation Index
> Fetch the complete documentation index at: https://learn.acadlink.app/llms.txt
> Use this file to discover all available pages before exploring further.

# Types of Arrays

> 1D, 2D, and multi-dimensional arrays in C

# Types of Arrays in C

Arrays in C are classified by their **number of dimensions** — how many indices are needed to access an element.

***

## 1. One-Dimensional Array (1D)

The simplest array — stores elements in a **single row**. One index is enough to access any element.

**Syntax:**

```c theme={null}
data_type array_name[size];
```

**Example:**

```c theme={null}
#include <stdio.h>
int main() {
    int numbers[5] = {10, 20, 30, 40, 50};
    for (int i = 0; i < 5; i++) {
        printf("%d ", numbers[i]);
    }
    return 0;
}
// Output: 10 20 30 40 50
```

***

## 2. Two-Dimensional Array (2D)

Stores elements in **rows and columns** — like a matrix or table. Two indices are needed: `[row][column]`.

**Syntax:**

```c theme={null}
data_type array_name[rows][columns];
```

**Example:**

```c theme={null}
#include <stdio.h>
int main() {
    int matrix[2][3] = {{1, 2, 3}, {4, 5, 6}};
    for (int i = 0; i < 2; i++) {
        for (int j = 0; j < 3; j++) {
            printf("%d ", matrix[i][j]);
        }
        printf("\n");
    }
    return 0;
}
```

**Output:**

```
1 2 3
4 5 6
```

**Memory layout of `matrix[2][3]`:**

```
       Col 0  Col 1  Col 2
Row 0:   1      2      3
Row 1:   4      5      6
```

***

## 3. Multi-Dimensional Array

Has **more than two dimensions**. Think of it as an array of 2D arrays. Used for complex data structures like 3D matrices or cubic grids.

**Syntax of a 3D array:**

```c theme={null}
data_type array_name[depth][rows][columns];
```

**Example:**

```c theme={null}
#include <stdio.h>
int main() {
    int cube[2][2][2] = {
        {{1, 2}, {3, 4}},
        {{5, 6}, {7, 8}}
    };
    for (int i = 0; i < 2; i++) {
        for (int j = 0; j < 2; j++) {
            for (int k = 0; k < 2; k++) {
                printf("%d ", cube[i][j][k]);
            }
            printf("\n");
        }
        printf("\n");
    }
    return 0;
}
```

**Output:**

```
1 2
3 4

5 6
7 8
```

***

## Comparison

| Type | Indices | Access         | Use Case         |
| ---- | ------- | -------------- | ---------------- |
| 1D   | 1       | `arr[i]`       | List of values   |
| 2D   | 2       | `arr[i][j]`    | Tables, matrices |
| 3D   | 3       | `arr[i][j][k]` | 3D grids         |