This happens because of partial array initialization rules in C

How Partial Initialization Works?

• When an array is partially initialized, the remaining elements are automatically set to 0

• This follows the C standard (C99 and later), which ensures that any missing elements in an initializer list are set to zero

• The equivalent explicit initialization would be:

    int arr[5] = {1, 2, 3, 0, 0};

What If You Don’t Initialize At All?

• If you declare an array without initializing, like this:

    int arr[5];  // Uninitialized array

• It contains garbage values (random data from memory)

Key Takeaway:

• Partial initialization fills remaining elements with 0

• Uninitialized arrays contain garbage values

• To explicitly zero out an array, use {0}:

    int arr[5] = {0};  // All elements set to 0