Note that Perl arrays are most definitely not linked lists. They are neat, however.

What you may be remembering is that pulling things off of the front of an array is nearly as efficient as popping them off of the back of an array. This is because Perl doesn't bother to shift all of the elements down until the gap in front gets big enough. But removing items from the middle of an array requires that one end (or the other?) be shifted.

The drastic difference in benchmark times confuses me. Update: No, "sub btrott" isn't broken (my debugging was). Hmmm....

Update 2: Never underestimate the slowness of Perl's opcode machinery. The "map" version loses because it executes 10_000 statements while the "splice" version only executes 100. While each "splice" statement has to copy a big chunk of the 10_000-element array, Perl's overhead swamps that. With the number of elements to be removed raised to 5_000, the "map" version is faster.

        - tye (but my friends call me "Tye")

In reply to RE: RE: Re: Removing certain elements from an array by tye
in thread Removing certain elements from an array by Anonymous Monk

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