Function and Array in C

Function and Array in C

In this tutorial, we will learn about function and array in the C programming language like how to pass and use and one dimension and multi-dimension array in C program.

One-Dimension Array and Function in C

While passing arrays as arguments to the function, only the name of the array is passed

 #include <stdio.h>  
 float average(float number[])  
 {  
   int i;  
   float avg, sum = 0.0;  
   for (i = 0; i < 6; ++i) {  
     sum += age[i];  
   }  
   avg = (sum / 6);  
   return avg;  
 }  
 int main()​  
 {  
   float avg, number[] = { 23.4, 55, 22.6, 3, 40.5, 18 };  
   avg = average(number); // Only name of array is passed as argument.  
   printf("Average age=%.2f", avg);  
   return 0;  
 }  

Two-Dimension Array and Function in C

When dimensions available globally we can pass two dimension array and use it similar to one dimension array.

Example

 #include <stdio.h>   
 const int M = 3;   
 const int N = 3;   
 void print(int arr[M][N])   
 {   
   int i, j;   
   for (i = 0; i < M; i++)   
    for (j = 0; j < N; j++)   
     printf("%d ", arr[i][j]);   
 }   
 int main()   
 {   
   int arr[M][N] = {{1, 2, 3}, {4, 5, 6}, {7, 8, 9}};   
   print(arr);   
   return 0;   
 }   

But when dimensions are not available globally then we have to use a pointer in order to pass an array to a function in c.
Example

 #include <stdio.h>   
 void print(int *arr, int m, int n)   
 {   
   int i, j;   
   for (i = 0; i < m; i++)   
    for (j = 0; j < n; j++)   
     printf("%d ", *((arr+i*n) + j));   
 }   
 int main()   
 {   
   int arr[][3] = {{1, 2, 3}, {4, 5, 6}, {7, 8, 9}};   
   int m = 3, n = 3;   
   print((int *)arr, m, n);   
   return 0;   
 }   

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