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i am trying to copy parts of an array to a new array and searched for a solution, but al those solutions were allot of coding or were not exactly what i was looking for. it might be that i searched wrong on google, but sorry if the answer to this is to easy to find, i couldnt find it.

i have array A

string[] A = {"A", "B", "C", "D", "E", "F"};

i tried to copy parts of it to array B using

string[] B = new string[2]; Array.Copy(A, 0, B, 0, 2)

but this just gives a fixed part of array A back so array B consists of "A" and "B".

is there also a way to give array B values 0, 1, 4, 5. so it gives me "A" "B" "E" and "F"

also sorry for bad english it is not my native language, and i tried to search on google for :

allot of the results of my first searches got me to pages about how to get an 2D array but that is not what i need. "How to copy 2 parts of an array to a new array" what lead me to array.copy tag after that i tried to look up "array.copy manual" but that only lead me to beleave it cant be done with array.copy so does anyone know how to do this in a compact code?

again. sorry if this answer is to obvious.

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3 Answers 3

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is there also a way to give array B values 0, 1, 4, 5. so it gives me "A" "B" "E" and "F"

No, because B is an array of strings. However, you can start with a separate array of indexes, and copy from A based on them:

int[] indexes = new[] {0, 1, 4, 5};
string[] B = indexes.Select(i => A[i]).ToArray();
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3 Comments

nice solution. only could be wrong on bound checking. int[] = new[] { 0,1, 15 }; might be: string[] B = indexes.Where(i => i < A.Length).Select(i => A[i]).ToArray();
@JeroenvanLangen OP's the one constructing the array of indexes, so observing the proper bounds is on him.
yours is more profesional it works i found a solution myself just now, but ill use yours and put mine in comment under it for refference purposes thank you.
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One way could be:

var indices = new[] { 0, 1, 4, 5 };
var copy = A.Where((s, i) => indices.Contains(i)).ToArray();
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It's better to use HashSet of indexes, instead of integer array in this case, since Contains is not too fast on an array (full search each time)
A hashset is not usefull when using 5 items, But I would upgrade it, when I didn't know the numbers.
Sure, 5 items does not matter. Just thought of a more "generic" case :)
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uhm i just went booging arround with my code and this works i guess:

string[] A = {"A", "B", "C", "D", "E", "F"}; string[] B = new string[4]; Array.Copy(A, 0, B, 0, 2) Array.Copy(A, 4, B, 2, 2)

it gives array B values A B E and F

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I can hardly believe you can put 4 values in an array of length 3 :)
oh ye sorry hihi it works it had to be 4 ill edit it.

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