fastes way to search an array?

[Tiemo Hollmann TB]

Hello,

I have an array with 20000 records, where I want to extract all records,
which either "begins with" or "contains" a search string.

Up to now I just loop thru the whole array, do the compare and extract the
result records. I wonder, if there is a way to speed up this search? E.g.,
does it makes a difference, if I compare the string in the key or the data
of the array while looping thru? I mean, would it make a difference, if I
would create an "associative" array, where my search looks up in the keys of
the array, either by looping thru the array, or by extracting first the keys
of the array into a separate variable, instead in the data of the original
array?

Would it make a difference looping thru a variable, which just contains the
keys of the array, instead of looping thru the complete array, because of
the smaller "footprint" in the memory?

Or shouldn't I care about these differences and just let LC makes its job?

Any experiences welcome,

Tiemo