C Passing an Entire Array to a Function

Passing an Entire Array to a Function

Array elements are always stored in continuous memory locations.

This C program passes the entire array to the function instead of individual elements in the array.

Array can be passed to the function using the address of the first element of the array.

Address of first element is accessed using any of the below statement.

&array_name[0]
or
array_name

C Program Example Passing Entire Array using Address of First Array Element

#include<stdio.h>
                                                                                
int sum(int*, int);                                                             
                                                                                
void main()                                                                     
{                                                                               
    int total = 0;                                                              
    int numbers[] = {10, 20, 30, 40, 50};                                       
    total = sum(&numbers[0], 5);                                                
    printf("Sum: %d", total);                                                   
}                                                                               
                                                                                
int sum(int *num, int n)                                                        
{                                                                               
    int total = 0, i = 1;                                                       
    while(i<=n)                                                                 
    {                                                                           
        printf("Element %d: %d\n", i, *num);                                    
        total += *num;                                                          
        num++;                                                                  
        i++;                                                                    
    }                                                                           
    return total;                                                               
}   

$ cc passing-array-to-function.c
$ ./a.out 
Element 1: 10
Element 2: 20
Element 3: 30
Element 4: 40
Element 5: 50
Sum: 150

C Program Example Passing Entire Array using Array Variable Name

#include<stdio.h>                                                            
                                                                                
int sum(int*, int);                                                             
                                                                                
void main()                                                                     
{                                                                               
    int total = 0;                                                              
    int numbers[] = {10, 20, 30, 40, 50};                                       
    total = sum(numbers, 5);                                                    
    printf("Sum: %d", total);                                                   
}                                                                               
                                                                                
int sum(int *num, int n)                                                        
{                                                                               
    int total = 0, i = 1;                                                       
    while(i<=n)                                                                 
    {                                                                           
        printf("Element %d: %d\n", i, *num);                                    
        total += *num;                                                          
        num++;                                                                  
        i++;                                                                    
    }                                                                           
    return total;                                                               
}                                                                               

$ cc passing-array-to-function.c
$ ./a.out 
Element 1: 10
Element 2: 20
Element 3: 30
Element 4: 40
Element 5: 50
Sum: 150