How to Pass a 3D Array to a Function in C?

Last Updated : 24 Jun, 2024

A 3D array (or three-dimensional array) in C is a multi-dimensional array that contains multiple layers of two-dimensional arrays stacked on top of each other. It stores elements that can be accessed using three indices: the depth index, row index, and column index. In this article, we will learn how to pass a 3D array to a function in C.

Passing 3D Array as Parameter to a Function in C

We cannot directly pass a 3D array to a function just like we do one-dimensional arrays. Instead, we must pass the 3D array to function as a pointer. When doing so, the array undergoes array decay , losing information about its dimensions. Therefore, we must pass the dimensions of the array separately.

Syntax

functionType funcName(type (*arr)[cols][depth], int rows, int cols, int depth)

Here,

funcName: It is the name of the function.
arr: It is the pointer which points to the 3D array.
rows: It represents the number of 2D arrays.
cols: It represents the number of rows in each 2D array.
depth: It represents the number of columns in each 2D array.

C program to pass a 3D array to a function

The following program illustrates how we can pass a 3D array to a function in C.

// C program to pass a 3D array to a function

#include <stdio.h>

// Function to print the elements of a 3D array
void printArray(int arr[][3][3], int rows, int cols,
                int depth)
{
    printf("Elements of the 3D array:\n");
    // Loop through each element in the 3D array
    for (int i = 0; i < rows; ++i) {
        for (int j = 0; j < cols; ++j) {
            for (int k = 0; k < depth; ++k) {
                // Print each element
                printf("%d   ", arr[i][j][k]);
            }
            // Printing a new line at the end of each column
            printf("\n");
        }
        // Printing a new line at the end of each row
        printf("\n");
    }
}

int main()
{
    // Initialize the 3D array with fixed sizes
    int arr[3][3][3] = {
        { { 10, 20, 30 }, { 40, 50, 60 }, { 70, 80, 90 } },
        { { 1, 2, 3 }, { 4, 5, 6 }, { 7, 8, 9 } },
        { { 190, 200, 210 },
          { 220, 230, 240 },
          { 250, 260, 270 } }
    };

    // Declare the dimensions of the array
    int rows = 3;
    int cols = 3;
    int depth = 3;

    // Pass the 3D array to the function
    printArray(arr, rows, cols, depth);

    return 0; // Return 0 to indicate successful execution
}

Output

Elements of the 3D array:
10   20   30   
40   50   60   
70   80   90   

1   2   3   
4   5   6   
7   8   9   

190   200   210   
220   230   240   
250   260   270

Time Complexity: O(1), as the time complexity of passing is not dependent on array size.
Auxiliary Space: O(1)