# Multi dimensional array

**URL:** <https://www.ruby-forum.com/t/multi-dimensional-array/100993>\
**Category:** Rails\
**Created:** [August 2, 2006, 3:42pm UTC](https://www.ruby-forum.com/t/multi-dimensional-array/100993 "2006-08-02T15:42:27Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![narayana](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/n/f6c823/32.png) [@narayana](https://www.ruby-forum.com/u/narayana)\
**Post date:** [August 2, 2006, 3:42pm UTC](https://www.ruby-forum.com/t/multi-dimensional-array/100993/1 "2006-08-02T15:42:27Z")

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how to implement multi dimensional array in ruby  
in ruby multi dimension array look like tree structure  
plz help me & explain with code  
have a pleasant day  
thx  
narayana

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<div class="post-metadata">

**Author:** ![narayana](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/n/f6c823/32.png) [@narayana](https://www.ruby-forum.com/u/narayana)\
**Post date:** [August 3, 2006, 12:57am UTC](https://www.ruby-forum.com/t/multi-dimensional-array/100993/2 "2006-08-03T00:57:16Z")

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Narayana Karthik wrote:

> how to implement multi dimensional array in ruby  
> in ruby multi dimension array look like tree structure  
> plz help me & explain with code  
> have a pleasant day  
> thx  
> narayana

While a “true” multi-dimensional array is not in the standard ruby  
library, you can fake it by having arrays of array pretty easily.

def multiplaction\_table(limit)  
output = []  
limit.times do |x|  
output[x] = []  
limit.times do |y|  
output[x][y] = x \* y  
end  
end

output  
end

result = multiplaction\_table(10)  
result[5][8] #=\> 40  
result[6][6] #=\> 36  
result[2][3] #=\> 6

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<div class="post-metadata">

**Author:** ![narayana](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/n/f6c823/32.png) [@narayana](https://www.ruby-forum.com/u/narayana)\
**Post date:** [August 3, 2006, 12:40pm UTC](https://www.ruby-forum.com/t/multi-dimensional-array/100993/3 "2006-08-03T12:40:24Z")

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Karthik

below are two examples first is for 2 dimensional array and second for 3  
dimension

irb(main):001:0\> mar = [[1,2],[3,4],[5,6]] #this creates 2 dimensional  
array  
called mar  
=\> [[1, 2], [3, 4], [5, 6]]  
irb(main):002:0\> mar[1][0] #to access value 3 we have to access 2nd  
element  
of mar which is an array and then 1st element of that array  
=\> 3  
irb(main):003:0\> mar3 = [[[1,2],[3,4]], [[5,6],[7,8]], [[9,10],[11,12]]]

# 

this creates 3 dimensional array mar3  
=\> [[[1, 2], [3, 4]], [[5, 6], [7, 8]], [[9, 10], [11, 12]]]  
irb(main):004:0\> mar3[2][1][1] # value 12 is in 3rd element of mar3, in  
it  
its the 2nd element is [11,12] and in it 2nd element is value 12  
=\> 12  
irb(main):005:0\>

I hope this helps  
-daya