Working with Transpose functions result in error

consider the following array

arr = [["Locator", "Test1", "string1","string2","string3","string4"],
["$LogicalName", "Create Individual Contact","value1","value2"]]


Desired result:

[Test1=>{"string1"=>"value1","string2"=>"value2","string3"=>"","string4"=>""}]


When I do transpose, it gives me the error by saying second element of the array is not the length of the first element in the array,

Uncaught exception: element size differs (2 should be 4)


so is there any to add empty string in the place where there is no element and can perform the transpose and then create the hash as I have given above? The array may consist of many elements with different length but according to the size of the first element in the array, every other inner array has to change by inserting empty string and then I can do the transpose. Is there any way?

transpose

arr

"Test1"

arr[0][1]

"stringX"

"valueX"

3 Answers
3

It sounds like you might want Enumerable#zip:

Enumerable#zip

headers, *data_rows = input_data
headers.zip(*data_rows)
# => [["Locator", "$LogicalName"], ["Test1", "Create Individual Contact"],
# ["string1", "value1"], ["string2", "value2"], ["string3", nil], ["string4", nil]]


""

map

nil

p result[1..-1].map{|dataRow| result[0].zip(dataRow).to_h}

If you wish to transpose an array of arrays, each element of the array must be the same size. Here you would need to do something like the following.

arr = [["Locator", "Test1", "string1","string2","string3","string4"],
["$LogicalName", "Create Individual Contact","value1","value2"]]

keys, vals = arr
#=> [["Locator", "Test1", "string1", "string2", "string3", "string4"],
# ["$LogicalName", "Create Individual Contact", "value1", "value2"]]
idx = keys.index("Test1") + 1
#=> 2

{ "Test1" => [keys[idx..-1],
vals[idx..-1].
concat(['']*(keys.size - vals.size))].
transpose.
to_h }
#=> {"Test1"=>{"string1"=>"value1", "string2"=>"value2", "string3"=>"", "string4"=>""}}


It is not strictly necessary to define the variables keys and vals, but that avoids the need to create those arrays multiple times. It reads better as well, in my opinion.

keys

vals

The steps are as follows. Note keys.size #=> 6 and vals.size #=> 4.

keys.size #=> 6

vals.size #=> 4

a = vals[idx..-1]
#=> vals[2..-1]
#=> ["value1", "value2"]
b = [""]*(keys.size - vals.size)
#=> [""]*(4 - 2)
#=> ["", ""]
c = a.concat(b)
#=> ["value1", "value2", "", ""]
d = keys[idx..-1]
#=> ["string1", "string2", "string3", "string4"]
e = [d, c].transpose
#=> [["string1", "value1"], ["string2", "value2"], ["string3", ""], ["string4", ""]]
f = e.to_h
#=> {"string1"=>"value1", "string2"=>"value2", "string3"=>"", "string4"=>""}
f = e.to_h
#=> { "Test1" => f }


Find the longest Element in your Array and make sure every other element has the same length - loop and add maxLength - element(i).length amount of "" elements.

maxLength - element(i).length

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