# How to copy arrays? **URL:** \ **Category:** ruby-talk\ **Created:** [21 November 2007 03:20 UTC](https://rubytalk.org/t/how-to-copy-arrays/42387 "2007-11-21T03:20:15Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![Martin\_Durai](https://avatars.discourse-cdn.com/v4/letter/m/d2c977/32.png) [@Martin\_Durai](https://rubytalk.org/u/Martin_Durai)\ **Post date:** [21 November 2007 03:20 UTC](https://rubytalk.org/t/how-to-copy-arrays/42387/1 "2007-11-21T03:20:15Z")
I came accross another problem, how to copy arrays? Actually i need to copy array just like in java. i will include the source code of java. The same functionality i need in ruby. please any body help me with this      System.arraycopy(elName, 0, arr, 0, elStackSize); I need a way to do samething in ruby. please any body help me with code for arraycopy. thanks in advance > **路路路** > > -- > Posted via [http://www.ruby-forum.com/](http://www.ruby-forum.com/). ---
**Author:** ![Daniel\_N1](https://avatars.discourse-cdn.com/v4/letter/d/df788c/32.png) [@Daniel\_N1](https://rubytalk.org/u/Daniel_N1)\ **Post date:** [21 November 2007 03:26 UTC](https://rubytalk.org/t/how-to-copy-arrays/42387/2 "2007-11-21T03:26:49Z")
The java doesn't mean anything to me 馃檪 That make me very happy. @array.dup is the way to copy any object in ruby > **路路路** > > On Nov 21, 2007 2:20 PM, Martin Durai \ wrote: > > > I came accross another problem, how to copy arrays? Actually i need to > > copy array just like in java. i will include the source code of java. > > The same functionality i need in ruby. please any body help me with this > > > >     System.arraycopy(elName, 0, arr, 0, elStackSize); > > > > I need a way to do samething in ruby. please any body help me with code > > for arraycopy. > > > > thanks in advance ---
**Author:** ![Martin\_Durai](https://avatars.discourse-cdn.com/v4/letter/m/d2c977/32.png) [@Martin\_Durai](https://rubytalk.org/u/Martin_Durai)\ **Post date:** [21 November 2007 03:38 UTC](https://rubytalk.org/t/how-to-copy-arrays/42387/3 "2007-11-21T03:38:36Z")
Thank you daniel, but my functionality is not return as a array. I need to copy a source array to a destination array. Thank you in advance > **路路路** > > -- > Posted via [http://www.ruby-forum.com/](http://www.ruby-forum.com/). ---
**Author:** ![Gregory\_Seidman](https://avatars.discourse-cdn.com/v4/letter/g/eb9ed0/32.png) [@Gregory\_Seidman](https://rubytalk.org/u/Gregory_Seidman)\ **Post date:** [21 November 2007 03:42 UTC](https://rubytalk.org/t/how-to-copy-arrays/42387/4 "2007-11-21T03:42:01Z")
> Thank you daniel, but my functionality is not return as a array. > I need to copy a source array to a destination array. def java\_inspired\_method\_sans\_idiomatic\_ruby(destination\_array)   destination\_array.replace @my\_array end > Thank you in advance --Greg > **路路路** > > On Wed, Nov 21, 2007 at 12:38:36PM +0900, Martin Durai wrote: ---
**Author:** ![Daniel\_N1](https://avatars.discourse-cdn.com/v4/letter/d/df788c/32.png) [@Daniel\_N1](https://rubytalk.org/u/Daniel_N1)\ **Post date:** [21 November 2007 03:44 UTC](https://rubytalk.org/t/how-to-copy-arrays/42387/5 "2007-11-21T03:44:51Z")
I don't understand what your asking then. This is a fairly standard way to copy an object. @array = [1,2,3,4,5] @new\_array = @array.dup > **路路路** > > On Nov 21, 2007 2:38 PM, Martin Durai \ wrote: > > > Thank you daniel, but my functionality is not return as a array. > > I need to copy a source array to a destination array. > > > > Thank you in advance > > -- > > Posted via [http://www.ruby-forum.com/\](http://www.ruby-forum.com/%5C). ---
**Author:** ![\_Pena\_Botp1](https://avatars.discourse-cdn.com/v4/letter/_/94ad74/32.png) [@\_Pena\_Botp1](https://rubytalk.org/u/_Pena_Botp1)\ **Post date:** [21 November 2007 04:14 UTC](https://rubytalk.org/t/how-to-copy-arrays/42387/6 "2007-11-21T04:14:16Z")
On Behalf Of Martin Durai: # Thank you daniel, but my functionality is not return as a array. # I need to copy a source array to a destination array. i think you only want to copy a part (the whole is trivial) of the array and insert it to another array, no? a #=\> [1, 2, 3, 4] b #=\> [5, 6, 7, 8, 9, 10] a[1,1] #=\> [2] b[2..-2] #=\> [7, 8, 9] a[1,1]=b[2..-2] #=\> [7, 8, 9] a #=\> [1, 7, 8, 9, 3, 4] or maybe just plain insert it, a[0] #=\> 1 b[0,2] #=\> [5, 6] a[0]=b[0,2] #=\> [5, 6] a #=\> [[5, 6], 7, 8, 9, 3, 4] kind regards -botp ---
**Author:** ![Robert\_K1](https://yyz1.discourse-cdn.com/flex029/user_avatar/rubytalk.org/robert_k1/32/1830_2.png) [@Robert\_K1](https://rubytalk.org/u/Robert_K1)\ **Post date:** [21 November 2007 07:00 UTC](https://rubytalk.org/t/how-to-copy-arrays/42387/7 "2007-11-21T07:00:01Z")
Maybe before we go off guessing you can show a bit more of your code. While there are methods to copy and insert into another array, maybe there is a more efficient solution. Cheers   robert > **路路路** > > On 21.11.2007 04:38, Martin Durai wrote: > > > Thank you daniel, but my functionality is not return as a array. > > I need to copy a source array to a destination array. ---
**Author:** ![Robert\_K1](https://yyz1.discourse-cdn.com/flex029/user_avatar/rubytalk.org/robert_k1/32/1830_2.png) [@Robert\_K1](https://rubytalk.org/u/Robert_K1)\ **Post date:** [21 November 2007 07:00 UTC](https://rubytalk.org/t/how-to-copy-arrays/42387/8 "2007-11-21T07:00:02Z")
I meant to include this irb(main):007:0\> a=(1..10).to\_a =\> [1, 2, 3, 4, 5, 6, 7, 8, 9, 10] irb(main):008:0\> a[2,4]=%w{a b c} =\> ["a", "b", "c"] irb(main):009:0\> a =\> [1, 2, "a", "b", "c", 7, 8, 9, 10] irb(main):010:0\> a.concat %w{foo bar} =\> [1, 2, "a", "b", "c", 7, 8, 9, 10, "foo", "bar"] irb(main):011:0\> a =\> [1, 2, "a", "b", "c", 7, 8, 9, 10, "foo", "bar"] irb(main):012:0\>   robert > **路路路** > > On 21.11.2007 07:58, Robert Klemme wrote: > > > On 21.11.2007 04:38, Martin Durai wrote: > > > > > Thank you daniel, but my functionality is not return as a array. > > > I need to copy a source array to a destination array. > > > > Maybe before we go off guessing you can show a bit more of your code. While there are methods to copy and insert into another array, maybe there is a more efficient solution.