# Can i calculate the data number in array? **URL:** \ **Category:** Ruby\ **Created:** [June 28, 2007, 10:30am UTC](https://www.ruby-forum.com/t/can-i-calculate-the-data-number-in-array/108003 "2007-06-28T10:30:10Z")\ **Posts on this page:** 9\ **Page:** 1
**Author:** ![coolwong](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/c/d9b06d/32.png) [@coolwong](https://www.ruby-forum.com/u/coolwong)\ **Post date:** [June 28, 2007, 10:30am UTC](https://www.ruby-forum.com/t/can-i-calculate-the-data-number-in-array/108003/1 "2007-06-28T10:30:10Z")
```auto Array = ["a", "a", "a", "b", "b", “c”, "c", "c","d", "d", "e"] ``` Can i calculate the data in the Array??? a a a b b c c c d d e For example: ArrayNumber = [“3”, “2”, “3”, “2”, “1”] ---
**Author:** ![coolwong](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/c/d9b06d/32.png) [@coolwong](https://www.ruby-forum.com/u/coolwong)\ **Post date:** [June 28, 2007, 10:42am UTC](https://www.ruby-forum.com/t/can-i-calculate-the-data-number-in-array/108003/2 "2007-06-28T10:42:20Z")
d=[“a”, “a”, “a”, “b”, “b”, “c”, “c”, “c”,“d”, “d”, “e”] p d dd={} d.each do |v| dd[v]||=0 dd[v]+=1 end p dd p dd.values ---
**Author:** ![coolwong](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/c/d9b06d/32.png) [@coolwong](https://www.ruby-forum.com/u/coolwong)\ **Post date:** [June 28, 2007, 10:43am UTC](https://www.ruby-forum.com/t/can-i-calculate-the-data-number-in-array/108003/3 "2007-06-28T10:43:58Z")
gz zz wrote: > d=[“a”, “a”, “a”, “b”, “b”, “c”, “c”, “c”,“d”, “d”, “e”] > p d > > dd={} > d.each do |v| > dd[v]||=0 > dd[v]+=1 > end > > p dd > > p dd.values But,I think ruby’s Hash is not ordered,so… ---
**Author:** ![coolwong](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/c/d9b06d/32.png) [@coolwong](https://www.ruby-forum.com/u/coolwong)\ **Post date:** [June 28, 2007, 10:45am UTC](https://www.ruby-forum.com/t/can-i-calculate-the-data-number-in-array/108003/4 "2007-06-28T10:45:50Z")
Dear Cool, maybe this is what you want: class Array def count ``` k=Hash.new(0) self.each{ |x| k[x]+=1 } k ``` end end my\_array = [“a”, “a”, “a”, “b”, “b”, “c”, “c”, “c”,“d”, “d”, “e”] my\_array.count It gives you a Hash, though, and the numbers are Integers, not Strings, but this seems more reasonable 🙂 Best regards, Axel ---
**Author:** ![coolwong](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/c/d9b06d/32.png) [@coolwong](https://www.ruby-forum.com/u/coolwong)\ **Post date:** [June 28, 2007, 12:11pm UTC](https://www.ruby-forum.com/t/can-i-calculate-the-data-number-in-array/108003/5 "2007-06-28T12:11:02Z")
On 28.06.2007 10:44, Axel E. wrote: > ``` > k=Hash.new(0) > > ``` > > my\_array = [“a”, “a”, “a”, “b”, “b”, “c”, “c”, “c”,“d”, “d”, “e”] > my\_array.count > > It gives you a Hash, though, and the numbers are Integers, > not Strings, but this seems more reasonable 🙂 Yes, I’d agree. Having tuples as return value is better because then you maintain relationship between items and item count. Btw, thanks for leaving the inject solution to me. 🙂 irb(main):005:0\> a = %w{a a a b b c c c d d e} =\> [“a”, “a”, “a”, “b”, “b”, “c”, “c”, “c”, “d”, “d”, “e”] irb(main):006:0\> a.inject(Hash.new(0)) {|h,x| h[x]+=1; h} =\> {“a”=\>3, “b”=\>2, “c”=\>3, “d”=\>2, “e”=\>1} irb(main):007:0\> a.inject(Hash.new(0)) {|h,x| h[x]+=1; h}.sort =\> [[“a”, 3], [“b”, 2], [“c”, 3], [“d”, 2], [“e”, 1]] Kind regards robert ---
**Author:** ![coolwong](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/c/d9b06d/32.png) [@coolwong](https://www.ruby-forum.com/u/coolwong)\ **Post date:** [June 28, 2007, 12:57pm UTC](https://www.ruby-forum.com/t/can-i-calculate-the-data-number-in-array/108003/6 "2007-06-28T12:57:09Z")
On 6/28/07, Robert K. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > Btw, thanks for leaving the inject solution to me. 🙂 > Shame on you!!! 😉 > But that is not what OP asked for (a|[]).map{|e|a.grep(e).size} ### I know it might not work as we use #=== here More generally we have therefore (a|[]).map{|e|a.select{|x|x==e}.size} Maybe OP preferred …).sort.map{… and sorry OP, I just needed this working break. Robert ---
**Author:** ![coolwong](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/c/d9b06d/32.png) [@coolwong](https://www.ruby-forum.com/u/coolwong)\ **Post date:** [June 28, 2007, 1:52pm UTC](https://www.ruby-forum.com/t/can-i-calculate-the-data-number-in-array/108003/7 "2007-06-28T13:52:14Z")
On 28.06.2007 12:56, Robert D. wrote: > On 6/28/07, Robert K. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > > > Btw, thanks for leaving the inject solution to me. 🙂 > > Shame on you!!! 😉 Um, why? Somehow I don’t get the joke, sorry. 🙂 > But that is not what OP asked for > > (a|[]).map{|e|a.grep(e).size} ### I know it might not work as we use > #=== here Sorry, Robert, but I don’t think this is what the OP was asking for: irb(main):001:0\> a = %w{a a a b b c c c d d e} =\> [“a”, “a”, “a”, “b”, “b”, “c”, “c”, “c”, “d”, “d”, “e”] irb(main):002:0\> a.map{|e|a.grep(e).size} =\> [3, 3, 3, 2, 2, 3, 3, 3, 2, 2, 1] Your solution repeats counts for the same string but as far as I can see from his original posting he wants counts for each string just once. > More generally we have therefore > > (a|[]).map{|e|a.select{|x|x==e}.size} > > Maybe OP preferred > …).sort.map{… > > and sorry OP, I just needed this working break. 🙂 Kind regards robert ---
**Author:** ![coolwong](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/c/d9b06d/32.png) [@coolwong](https://www.ruby-forum.com/u/coolwong)\ **Post date:** [June 28, 2007, 11:20pm UTC](https://www.ruby-forum.com/t/can-i-calculate-the-data-number-in-array/108003/8 "2007-06-28T23:20:54Z")
On 28.06.2007 16:11, Robert D. wrote: > On 6/28/07, Robert K. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > > > On 28.06.2007 12:56, Robert D. wrote: > > > > > On 6/28/07, Robert K. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > > =\> [3, 3, 3, 2, 2, 3, 3, 3, 2, 2, 1] > > Careful here Robert I wrote > > (a|[]) which is a more computation intensive way to write a.uniq. – > its a coding joke brrr Umpf! I actually overlooked that one. Somehow I read it as (a||[]). Duh! Sorry for the noise. Btw, that idiom was not part of my repertoire. So I actually learned something today - although I have to say I’d rather stick with #uniq - it’s easier for my brain. 🙂 Kind regards robert ---
**Author:** ![coolwong](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/c/d9b06d/32.png) [@coolwong](https://www.ruby-forum.com/u/coolwong)\ **Post date:** [June 28, 2007, 4:12pm UTC](https://www.ruby-forum.com/t/can-i-calculate-the-data-number-in-array/108003/9 "2007-06-28T16:12:39Z")
On 6/28/07, Robert K. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > On 28.06.2007 12:56, Robert D. wrote: > > > On 6/28/07, Robert K. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > > > > > Btw, thanks for leaving the inject solution to me. 🙂 > > > Shame on you!!! 😉 > > Um, why? Somehow I don’t get the joke, sorry. 🙂 > Really or are you metajoking?anyway to get out of recursive joke mode, > we are sometimes competing about #inject. > irb(main):002:0\> a.map{|e|a.grep(e).size} > =\> [3, 3, 3, 2, 2, 3, 3, 3, 2, 2, 1] > Careful here Robert I wrote (a|[]) which is a more computation intensive way to write a.uniq. – its a coding joke brrr Read my post please you can learn sooooo much. – this is a joke! Robert