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

In C++, a 3D array is a multidimensional array that has three dimensions, i.e. it can grow in three directions. In this article, we will learn how to pass a 3D array to a function in C++.

Pass a 3D Array to a Function in C++

Just like normal 1-dimensional arrays, we can't pass the array to a function directly, we must pass the 3D array to a function as a pointer. The array will suffer the array decay and lose the information about its dimensions so we need to pass the dimensions separately.

Syntax

function_type name (type (*arr)[col][dpt], int row, int col, int dpt)

where *arr is a pointer to a 3D array with dimensions row, col, and dpt.

C++ Program to Pass a 3D Array to a Function

// C++ program to pass a 3D array to a function
#include <iostream>
using namespace std;

// function to print the elements of a 3D array
void printArray(int arr[][3][3], int row, int col, int dpt)
{
    for (int i = 0; i < row; ++i) {
        for (int j = 0; j < col; ++j) {
            for (int k = 0; k < dpt; ++k) {
                cout << arr[i][j][k] << " ";
            }
            cout << endl;
        }
        cout << endl;
    }
}

int main()
{
    // intialize the 3D array
    int arr[3][3][3] = {
        { { 1, 2, 3 }, { 4, 5, 6 }, { 7, 8, 9 } },
        { { 10, 11, 12 }, { 13, 14, 15 }, { 16, 17, 18 } },
        { { 19, 20, 21 }, { 22, 23, 24 }, { 25, 26, 27 } }
    };
    // pass the 3D array to the function
    printArray(arr, 3, 3, 3);

    return 0;
}

1 2 3 
4 5 6 
7 8 9 

10 11 12 
13 14 15 
16 17 18 

19 20 21 
22 23 24 
25 26 27 

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