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

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 } 

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)