How to get the length of an array in C?

C - Size of an array

Code:

int size = sizeof(arr)/sizeof(arr[0]); 

Example:

#include <stdio.h>
int main()
{
 int arr[] = { 10, 20, 30, 40, 50, 60 };
 int size_arra = (arr, sizeof arr / sizeof *arr);
 printf("Number of elements in arr[]:  %d", size_arra);
}

Output:

6

Note: You can use the sizeof operator to obtain the size (in bytes) of the data type of its operand. The operand may be an actual type specifier (such as int or float), as well as any valid expression. When the operand is a type name, it must be enclosed in parentheses.

Print an array elements using array size:

C Code:

#include <stddef.h>
#include <stdio.h>

static const int values[] = { 10, 20, 30, 40, 50, 60 };
#define ARRAYSIZE(x) (sizeof x/sizeof x[0])
int main (int argc, char *argv[])
{
   size_t i;
   printf("Size of the array: %d\n",ARRAYSIZE(values));
   for (i = 0; i < ARRAYSIZE(values); i++)
   {
       printf("%d ", values[i]);
   }
   return 0;
}

Output:

Size of the array: 6
10 20 30 40 50 60