Correct option to declare an array in C?

Question

We can declare the array in the following two ways, I want to know what is the re-commanded way -

arr[]={1,2,3,4,5,6,7,8,9,10};
arr[10]={1,2,3,4,5,6,7,8,9,10};

Answer 1

Both the option are same however preference is the first one as you leave it to the compiler for the size of the array which can avoid the unwanted mistake.