C Programming Arrays and Functions

C Programming Arrays and Functions 

In C programming, a single array element or an entire array can be passed to a function. Also, both one-dimensional and multi-dimensional array can be passed to function as argument.

Passing One-dimensional Array In Function

C program to pass a single element of an array to function

#include <stdio.h>

void display(int a)

   {

   printf("%d",a);

   }

int main(){

   int c[]={2,3,4};

   display(c[2]);  //Passing array element c[2] only.

   return 0;

}

Output

4

Single element of an array can be passed in similar manner as passing variable to a function.

Passing entire one-dimensional array to a function

While passing arrays to the argument, the name of the array is passed as an argument(,i.e, starting address of memory area is passed as argument).

Write a C program to pass an array containing age of person to a function. This function should find average age and display the average age in main function.

#include <stdio.h>

float average(float a[]);

int main(){

     float avg, c[]={23.4, 55, 22.6

, 3, 40.5, 18};

     avg=average(c);   /* Only name of array is passed as argument. */

     printf("Average age=%.2f",avg);

     return 0;

   }

float average(float a[]){ 

     int i;

     float avg, sum=0.0;

     for(i=0;i<6;++i){

       sum+=a[i];

     }

     avg =(sum/6);

     return avg;

}

Output

Average age=27.08

Passing Multi-dimensional Arrays to Function

To pass two-dimensional array to a function as an argument, starting address of memory area reserved is passed as in one dimensional array

Example to pass two-dimensional arrays to function

 #include void Function(int c[2][2]); int main(){ int c[2][2],i,j; printf("Enter 4 numbers:\n"); for(i=0;i<2;++i) for(j=0;j<2;++j){ scanf("%d",&c[i][j]); } Function(c); /* passing multi-dimensional array to function */ return 0; } void Function(int c[2][2]){ /* Instead to above line, void Function(int c[][2]){ is also valid */ int i,j; printf("Displaying:\n"); for(i=0;i<2;++i) for(j=0;j<2;++j) printf("%d\n",c[i][j]); }

Output

Enter 4 numbers:

2

3

4

5

Displaying:

2

3

4

5