How does below method of array initialization differ in context to array bounds checking?

问题

Why does int arr[2]={10,20,30,40,50} leads to error? Why can't this initialization escape error by Array Bound Checking?

int arr[2] ;
arr[0]=10, arr[1]=20, arr[3]=30, arr[4]=40;

Doesn't cause error in context to C language by array bound checking?

回答1:

There is no runtime array bounds check in C. You are free to obliterate whatever is in memory. The 1st example you show, is a compile-time structure, so the compiler know that you declared an array of size 2, and that the initialization has > 2 elements.

来源：https://stackoverflow.com/questions/46144353/how-does-below-method-of-array-initialization-differ-in-context-to-array-bounds