Accessing single-dimensional array entries with index array

Question

I am trying to access elements in a single-dimensional "data" array (string or double) via another array that contains the indices I wish to extract:

string[] myWords = {"foo", "overflow", "bar", "stack"};
int[] indices = {3, 1};

string[] someWords = myWords[indices]; // Extract entries number three and one.

The last line is refused by the compiler. What I'd like to see is someWords == {"stack", "overflow"}.

As far as I know, this works in Matlab and Fortran, so is there any nice and elegant way to do this for arrays in C#? Lists are fine, too.

Array.GetValue(int[]) like in this question does not work in my case, since this method is for multidimensional arrays only.`

That looks like syntax that would work in a language from a different paradigm. In C#, array operations are much more manual; the LINQ answer works (a library doing the job) or you could implement it explicitly as a loop over the values in indices with a manually-constructed array containing the results. — Shibumi
– Shibumi, Commented Feb 10, 2014 at 18:00
Of course I could do it manually, but I was specifically looking for an elegant one-liner. — cuneus
– cuneus, Commented Feb 11, 2014 at 2:57

Andrei · Accepted Answer · 2014-02-10 18:08:43Z

4

if you can use LINQ, here is a way:

string[] someWords = indices.Select(index => myWords[index]).ToArray();

edited Feb 10, 2014 at 18:08

answered Feb 10, 2014 at 17:42

Andrei

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cuneus Over a year ago

Thanks, that looks exactly like the thing I was looking for! Will try it as soon as I get back to the code.

Sriram Sakthivel · Accepted Answer · 2014-02-10 17:48:34Z

1

Not sure this is what you're asking about.

string[] myWords = {"foo", "overflow", "bar", "stack"};
int[] indices = {3, 1};
string[] someWords = indices.Select(x=> myWords[x]).ToArray();

answered Feb 10, 2014 at 17:48

Sriram Sakthivel

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