To pass multidimensional arrays to a function, only the name of the array is passed to the function (similar to one-dimensional arrays).
Example 3: Pass two-dimensional arrays
#include <stdio.h>
void displayNumbers(int num[2][2]);
int main() {
int num[2][2];
printf("Enter 4 numbers:\n");
for (int i = 0; i < 2; ++i) {
for (int j = 0; j < 2; ++j) {
scanf("%d", &num[i][j]);
}
}
// pass multi-dimensional array to a function
displayNumbers(num);
return 0;
}
void displayNumbers(int num[2][2]) {
printf("Displaying:\n");
for (int i = 0; i < 2; ++i) {
for (int j = 0; j < 2; ++j) {
printf("%d\n", num[i][j]);
}
}
}
Output
Enter 4 numbers:
2
3
4
5
Displaying:
2
3
4
5
Notice the parameter int num[2][2] in the function prototype and function definition:
// function prototype
void displayNumbers(int num[2][2]);
This signifies that the function takes a two-dimensional array as an argument. We can also pass arrays with more than 2 dimensions as a function argument.
When passing two-dimensional arrays, it is not mandatory to specify the number of rows in the array. However, the number of columns should always be specified.
In C programming, you can pass an entire array to functions. Before we learn that, let’s see how you can pass individual elements of an array to functions.
#include <stdio.h>
void display(int age1, int age2) {
printf("%d\n", age1);
printf("%d\n", age2);
}
int main() {
int ageArray[] = {2, 8, 4, 12};
// pass second and third elements to display()
display(ageArray[1], ageArray[2]);
return 0;
}
Output
8
4
Here, we have passed array parameters to the display() function in the same way we pass variables to a function.
// pass second and third elements to display()
display(ageArray[1], ageArray[2]);
We can see this in the function definition, where the function parameters are individual variables:
void display(int age1, int age2) {
// code
}
Example 2: Pass Arrays to Functions
// Program to calculate the sum of array elements by passing to a function
#include <stdio.h>
float calculateSum(float num[]);
int main() {
float result, num[] = {23.4, 55, 22.6, 3, 40.5, 18};
// num array is passed to calculateSum()
result = calculateSum(num);
printf("Result = %.2f", result);
return 0;
}
float calculateSum(float num[]) {
float sum = 0.0;
for (int i = 0; i < 6; ++i) {
sum += num[i];
}
return sum;
}
Output
Result = 162.50
To pass an entire array to a function, only the name of the array is passed as an argument.
result = calculateSum(num);
However, notice the use of [] in the function definition.
float calculateSum(float num[]) {
... ..
}
This informs the compiler that you are passing a one-dimensional array to the function.
Example 1: Two-dimensional array to store and print values
// C program to store temperature of two cities of a week and display it.
#include <stdio.h>
const int CITY = 2;
const int WEEK = 7;
int main()
{
int temperature[CITY][WEEK];
// Using nested loop to store values in a 2d array
for (int i = 0; i < CITY; ++i)
{
for (int j = 0; j < WEEK; ++j)
{
printf("City %d, Day %d: ", i + 1, j + 1);
scanf("%d", &temperature[i][j]);
}
}
printf("\nDisplaying values: \n\n");
// Using nested loop to display vlues of a 2d array
for (int i = 0; i < CITY; ++i)
{
for (int j = 0; j < WEEK; ++j)
{
printf("City %d, Day %d = %d\n", i + 1, j + 1, temperature[i][j]);
}
}
return 0;
}
Output
City 1, Day 1: 33
City 1, Day 2: 34
City 1, Day 3: 35
City 1, Day 4: 33
City 1, Day 5: 32
City 1, Day 6: 31
City 1, Day 7: 30
City 2, Day 1: 23
City 2, Day 2: 22
City 2, Day 3: 21
City 2, Day 4: 24
City 2, Day 5: 22
City 2, Day 6: 25
City 2, Day 7: 26
Displaying values:
City 1, Day 1 = 33
City 1, Day 2 = 34
City 1, Day 3 = 35
City 1, Day 4 = 33
City 1, Day 5 = 32
City 1, Day 6 = 31
City 1, Day 7 = 30
City 2, Day 1 = 23
City 2, Day 2 = 22
City 2, Day 3 = 21
City 2, Day 4 = 24
City 2, Day 5 = 22
City 2, Day 6 = 25
City 2, Day 7 = 26
Example 2: Sum of two matrices
// C program to find the sum of two matrices of order 2*2
#include <stdio.h>
int main()
{
float a[2][2], b[2][2], result[2][2];
// Taking input using nested for loop
printf("Enter elements of 1st matrix\n");
for (int i = 0; i < 2; ++i)
for (int j = 0; j < 2; ++j)
{
printf("Enter a%d%d: ", i + 1, j + 1);
scanf("%f", &a[i][j]);
}
// Taking input using nested for loop
printf("Enter elements of 2nd matrix\n");
for (int i = 0; i < 2; ++i)
for (int j = 0; j < 2; ++j)
{
printf("Enter b%d%d: ", i + 1, j + 1);
scanf("%f", &b[i][j]);
}
// adding corresponding elements of two arrays
for (int i = 0; i < 2; ++i)
for (int j = 0; j < 2; ++j)
{
result[i][j] = a[i][j] + b[i][j];
}
// Displaying the sum
printf("\nSum Of Matrix:");
for (int i = 0; i < 2; ++i)
for (int j = 0; j < 2; ++j)
{
printf("%.1f\t", result[i][j]);
if (j == 1)
printf("\n");
}
return 0;
}
Output
Enter elements of 1st matrix
Enter a11: 2;
Enter a12: 0.5;
Enter a21: -1.1;
Enter a22: 2;
Enter elements of 2nd matrix
Enter b11: 0.2;
Enter b12: 0;
Enter b21: 0.23;
Enter b22: 23;
Sum Of Matrix:
2.2 0.5
-0.9 25.0
Example 3: Three-dimensional array
// C Program to store and print 12 values entered by the user
#include <stdio.h>
int main()
{
int test[2][3][2];
printf("Enter 12 values: \n");
for (int i = 0; i < 2; ++i)
{
for (int j = 0; j < 3; ++j)
{
for (int k = 0; k < 2; ++k)
{
scanf("%d", &test[i][j][k]);
}
}
}
// Printing values with proper index.
printf("\nDisplaying values:\n");
for (int i = 0; i < 2; ++i)
{
for (int j = 0; j < 3; ++j)
{
for (int k = 0; k < 2; ++k)
{
printf("test[%d][%d][%d] = %d\n", i, j, k, test[i][j][k]);
}
}
}
return 0;
}
