C language

Question

How can i pass only element to function
Example..

I want that if i input sum(arr[0],arr[1],arr[2])
Than it show sum of 0,1,2 element
But if i take input 0,1,2,3,4 than it show sum of it
Here is my try but i didn't get it
(This is just example it didn't work )
(It is for showing that i try to do it but it didn't work)

Int main()
{
Int Arr[5] = {1,1,2,3};
Printf("%d",sum(arr[2],arr[1]));
}

Sum(int arr[0],int arr[1])
{
Int sum =0;
For(int i=0;i<2;i++)
Sum=sum+arr[i];
Return 0;
}

Answer 1

Just send the entire array to the function. ( Make sure to keep track of its size though )