Comparing two arrays what the best most efficient way

[welchs101]

Hi,

I have two arrays. Both arrays contain file names. Both arrays are sorted in alphabetical order.

WHat i want to do is the following:
I want to compare one array to the other. If an entry in array1 is in array2 then i want to do "something". if an entry is in array1 but not in array2 then i dont care. If an entry is in array2 but not in array1 again i dont care.

any ideas on an efficient way to do this?

[Mordred]

Hi welchs101, the following is an example of comparing two String Arrays.

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[welchs101]

thanks for responding.

[Mordred]

No problem! And?

[DonkeyOte]

Mordred, I think the implication is that the Arrays need not be of the same dimension and/or items in the same order ... ie "work" may be item 2 in strArray2.

welchs101, you can either iterate the 2nd Array for each iteration of the 1st exiting upon match, e.g:

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alternatively apply a Match function (binary given sort) to array2 (use Index if multi dimensional - assume given subject matter that case is irrelevant):

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Given the speed of Arrays I suspect iteration would be quicker than the Match approach.

The fact that the arrays are sorted is helpful and with thought may permit some restrictions within the iteration, however, given the potential for missing items in either array it might not be as simple as appears at first glance.

[welchs101]

thanks guys...........very helpful indeed.