If perl wouldn't fill in the "buckets", then the buckets would contain random garbage. Since perl reuses memory, that garbage may well be old array elements. How would perl know which array elements are "valid" and which ones are "not filled in"?

Note that (internal, C-level) arrays contain pointers to SVs.

In reply to Re^2: Could we save the memory occupied by "undef" in an array? by JavaFan
in thread Could we save the memory occupied by "undef" in an array? by lightoverhead

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