# Nested array filling well.. but tricky search back **URL:** \ **Category:** Ruby\ **Created:** [September 24, 2007, 1:00pm UTC](https://www.ruby-forum.com/t/nested-array-filling-well-but-tricky-search-back/115360 "2007-09-24T13:00:46Z")\ **Posts on this page:** 1\ **Page:** 1
**Author:** ![Josselin](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/9de0a6/32.png) [@Josselin](https://www.ruby-forum.com/u/Josselin)\ **Post date:** [September 24, 2007, 1:00pm UTC](https://www.ruby-forum.com/t/nested-array-filling-well-but-tricky-search-back/115360/1 "2007-09-24T13:00:46Z")
thanks to your help… I got a nice nested array ALL\_CATEGORIES = [[[1, “category1”], [2, “category2”], [3, “category3”], [4, “category4”]], [[5, “category5”], [6, “category6”], [7, “category7”], [8, “category8”]], [[9, “category9”], [10, “category10”], [11, “category11”], [12, “category12”], [13, “category13”], [14, “category14”], [15, “category15”]], [[16, “category16”], [17, “category17”], [18, “category18”], [19, “category19”]], [[20, “category20”], [21, “category21”], [22, “category22”]], [[23, “category23”], [24, “category24”], [25, “category25”], [26, “category26”], [27, “category27”], [28, “category28”]], [[29, “category29”], [30, “category30”], [31, “category31”] so I can get : all categories of first domain ALL\_CATEGORIES[0] =\> [[1, “category1”], [2, “category2”], [3, “category3”], [4, “category4”]] first category of first domain ALL\_CATEGORIES[0][0] =\> [1, “category1”] category index of first category of first domain ALL\_CATEGORIES[0][0][0] =\> 1 category label of first category of first domain ALL\_CATEGORIES[0][0][1] =\> “category1” is there any easy way to find back the domain index from the category index ? or should I rewrite my array ? given category index 5 then domain index would be 1 I would find it in ALL\_CATEGORIES[1] =\> [[5, “category5”], [6, “category6”], [7, “category7”], [8, “category8”]] thanks fyh joss