# Convert an array to a hash **URL:** \ **Category:** Ruby\ **Created:** [December 5, 2009, 5:44am UTC](https://www.ruby-forum.com/t/convert-an-array-to-a-hash/179848 "2009-12-05T05:44:04Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![rubynut](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/8e8cbc/32.png) [@rubynut](https://www.ruby-forum.com/u/rubynut)\ **Post date:** [December 5, 2009, 5:44am UTC](https://www.ruby-forum.com/t/convert-an-array-to-a-hash/179848/1 "2009-12-05T05:44:04Z")
Helo, How to convert an array to a hash? for example, > x > =\> [“a”, “hello”, “b”, “world”, “c”, “welcome”, “d”, “baby”] to: > z > =\> {“a”=\>“hello”, “b”=\>“world”, “c”=\>“welcome”, “d”=\>“baby”} And, for creating an array quickly, I could say: x = %w/a hello b world c welcome d baby/ but how to creat a hash like this way? Thanks. ---
**Author:** ![rubynut](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/8e8cbc/32.png) [@rubynut](https://www.ruby-forum.com/u/rubynut)\ **Post date:** [December 5, 2009, 6:10am UTC](https://www.ruby-forum.com/t/convert-an-array-to-a-hash/179848/2 "2009-12-05T06:10:20Z")
Ruby N. wrote: > Helo, > > How to convert an array to a hash? > for example, > > > x > > =\> [“a”, “hello”, “b”, “world”, “c”, “welcome”, “d”, “baby”] > > to: > > > z > > =\> {“a”=\>“hello”, “b”=\>“world”, “c”=\>“welcome”, “d”=\>“baby”} > > And, for creating an array quickly, I could say: > > x = %w/a hello b world c welcome d baby/ > > but how to creat a hash like this way? I’m not sure why you want to do this in the first place, but check out the each\_slice method. > Thanks. Best, – Marnen Laibow-Koser [http://www.marnen.org](http://www.marnen.org) removed\_email\_address@domain.invalid ---
**Author:** ![rubynut](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/8e8cbc/32.png) [@rubynut](https://www.ruby-forum.com/u/rubynut)\ **Post date:** [December 5, 2009, 6:21am UTC](https://www.ruby-forum.com/t/convert-an-array-to-a-hash/179848/3 "2009-12-05T06:21:24Z")
irb(main):001:0\> a=[“a”, “hello”, “b”, “world”, “c”, “welcome”, “d”, “baby”] =\> [“a”, “hello”, “b”, “world”, “c”, “welcome”, “d”, “baby”] irb(main):002:0\> Hash[\*a] =\> {“a”=\>“hello”, “b”=\>“world”, “c”=\>“welcome”, “d”=\>“baby”} irb(main):003:0\> * * * [http://zed.0xff.me](http://zed.0xff.me) ---
**Author:** ![rubynut](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/8e8cbc/32.png) [@rubynut](https://www.ruby-forum.com/u/rubynut)\ **Post date:** [December 5, 2009, 9:24am UTC](https://www.ruby-forum.com/t/convert-an-array-to-a-hash/179848/4 "2009-12-05T09:24:05Z")
2009/12/5 Andrey Z. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid): > irb(main):001:0\> a=[“a”, “hello”, “b”, “world”, “c”, “welcome”, “d”, > “baby”] > =\> [“a”, “hello”, “b”, “world”, “c”, “welcome”, “d”, “baby”] > irb(main):002:0\> Hash[\*a] Thanks. What’s the “\*” before “a” then? ---
**Author:** ![rubynut](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/8e8cbc/32.png) [@rubynut](https://www.ruby-forum.com/u/rubynut)\ **Post date:** [December 5, 2009, 10:49am UTC](https://www.ruby-forum.com/t/convert-an-array-to-a-hash/179848/5 "2009-12-05T10:49:32Z")
On Sat, Dec 5, 2009 at 9:22 AM, Ruby N. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > 2009/12/5 Andrey Z. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid): > > > irb(main):001:0\> a=[“a”, “hello”, “b”, “world”, “c”, “welcome”, “d”, > > “baby”] > > =\> [“a”, “hello”, “b”, “world”, “c”, “welcome”, “d”, “baby”] > > irb(main):002:0\> Hash[\*a] > > Thanks. > What’s the “\*” before “a” then? It’s the splat operator. It’s used to “unarray” an array into its individual items to pass them to a method: irb(main):007:0\> def m(a,b,c) irb(main):008:1\> p a irb(main):009:1\> p b irb(main):010:1\> p c irb(main):011:1\> end =\> nil irb(main):012:0\> x = [1,2,3] =\> [1, 2, 3] irb(main):013:0\> m \*x 1 2 3 or to collect individual elements into an array when it appears in a lvalue: irb(main):014:0\> a,\*b = [1,2,3,4,5] =\> [1, 2, 3, 4, 5] irb(main):015:0\> a =\> 1 irb(main):016:0\> b =\> [2, 3, 4, 5] or argument list of a method: irb(main):020:0\> def m(a,\*b) irb(main):021:1\> p a irb(main):022:1\> p b irb(main):023:1\> end =\> nil irb(main):024:0\> m(1,2,3,4,5,6) 1 [2, 3, 4, 5, 6] Hope this helps, Jesus. ---
**Author:** ![rubynut](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/8e8cbc/32.png) [@rubynut](https://www.ruby-forum.com/u/rubynut)\ **Post date:** [December 5, 2009, 4:52pm UTC](https://www.ruby-forum.com/t/convert-an-array-to-a-hash/179848/6 "2009-12-05T16:52:23Z")
2009/12/5 Jesús Gabriel y Galán [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid): > It’s the splat operator. It’s used to “unarray” an array into its > individual items to pass them to a method: Ah, I got it, thanks~ ---
**Author:** ![rubynut](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/8e8cbc/32.png) [@rubynut](https://www.ruby-forum.com/u/rubynut)\ **Post date:** [December 5, 2009, 6:44am UTC](https://www.ruby-forum.com/t/convert-an-array-to-a-hash/179848/7 "2009-12-05T06:44:12Z")
Andrey Z. wrote: > irb(main):001:0\> a=[“a”, “hello”, “b”, “world”, “c”, “welcome”, “d”, > “baby”] > =\> [“a”, “hello”, “b”, “world”, “c”, “welcome”, “d”, “baby”] > irb(main):002:0\> Hash[\*a] > =\> {“a”=\>“hello”, “b”=\>“world”, “c”=\>“welcome”, “d”=\>“baby”} > irb(main):003:0\> > > * * * > > [http://zed.0xff.me](http://zed.0xff.me) Oh, right. I thought Hash had a constructor like that, but I couldn’t find it in the docs. Thanks! Best, – Marnen Laibow-Koser [http://www.marnen.org](http://www.marnen.org) removed\_email\_address@domain.invalid