Challenge 2: Directory Index Order When Only One Candidate Exists — Solution Walkthrough

What actually gets served:

index.php gets served. Even though the configured index list is
"index.html index.php" — meaning index.html is checked first — the
server only serves whichever candidate actually exists in that
directory. Since index.html isn't present at all, the server moves on
to the next candidate in the list, index.php, finds it, and serves
that instead.

Why the order still matters, even here:

The order determines *priority* among files that exist, not merely
which files are eligible. If this directory had contained both
index.html and index.php, the server would have served index.html
specifically because it's listed first — index.php would have been
ignored entirely in that case, regardless of which file might have
been more "correct" to serve. The order only becomes visible in this
particular exercise because there's no conflict to resolve — but it's
exactly the mechanism that would decide the outcome if both files
existed side by side.

WHY THIS WORKS AS AN ANSWER
------------------------------
This exercise checks that the directory-index mechanism from this
chapter is understood as "check candidates in order, serve the first
one that exists" rather than "always serve the first item in the
list regardless of whether it exists" — correctly explaining why the
list's order still matters, even in a case where only one candidate
happens to be present.