I suppose, lacking a CS background, I'm asking for trouble with a question like
this, but I might as well try:

Recently I wrote a script that compares lines in two files. I thought I'd done a
half-decent job of it until I found that a programmer at work had already done the
same thing in C, and the C program ran 75 times faster than the perl script. Oops.
(The substantial difference became apparent when the input files got fairly large.
The C program was able to go out for a nice leisurely lunch while the perl script was
still trying to figure out how to tie its shoelaces.)

Then, after reading one of the perl FAQ files referred to in a recent post here, I
re-wrote the script using hashes, not arrays. The C program remained faster than the
perl script--but the difference in execution times had been drastically reduced.

What is it about hashes that can make such a dramatic difference in
execution speed?

In reply to Why are hashes so much faster? by Anonymous Monk

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