Can't convert symbol to integer from hash table - ruby

Question

Edit: The issue is being unable to get the quantity of arrays within the hash, so it can be, x = amount of arrays. so it can be used as function.each_index{|x| code }
Trying to use the index of the amount of rows as a way of repeating an action X amount of times depending on how much data is pulled from a CSV file.
Terminal issued
=> Can't convert symbol to integer (TypeError)
Complete error:
=> ~/home/tests/Product.rb:30:in '[]' can't convert symbol into integer (TypeError) from ~home/tests/Product.rub:30:in 'getNumbRel'
from test.rb:36:in '<main>'
the function is that is performing the action is:
def getNumRel
if defined? #releaseHashTable
return #releaseHashTable[:releasename].length
else
#releaseHashTable = readReleaseCSV()
return #releaseHashTable[:releasename].length
end
end
The csv data pull is just a hash of arrays, nothing snazzy.
def readReleaseCSV()
$log.info("Method "+"#{self.class.name}"+"."+"#{__method__}"+" has started")
$log.debug("reading product csv file")
# Create a Hash where the default is an empty Array
result = Array.new
csvPath = "#{File.dirname(__FILE__)}"+"/../../data/addingProdRelProjIterTestSuite/releaseCSVdata.csv"
CSV.foreach(csvPath, :headers => true, :header_converters => :symbol) do |row|
row.each do |column, value|
if "#{column}" == "prodid"
proHash = Hash.new { |h, k| h[k] = [ ] }
proHash['relid'] << row[:relid]
proHash['releasename'] << row[:releasename]
proHash['inheritcomponents'] << row[:inheritcomponents]
productId = Integer(value)
if result[productId] == nil
result[productId] = Array.new
end
result[productId][result[productId].length] = proHash
end
end
end
$log.info("Method "+"#{self.class.name}"+"."+"#{__method__}"+" has finished")
#productReleaseArr = result
end

Answer 1

Sorry, couldn't resist, cleaned up your method.
# empty brackets unnecessary, no uppercase in method names
def read_release_csv
# you don't need + here
$log.info("Method #{self.class.name}.#{__method__} has started")
$log.debug("reading product csv file")
# you're returning this array. It is not a hash. [] is preferred over Array.new
result = []
csvPath = "#{File.dirname(__FILE__)}/../../data/addingProdRelProjIterTestSuite/releaseCSVdata.csv"
CSV.foreach(csvPath, :headers => true, :header_converters => :symbol) do |row|
row.each do |column, value|
# to_s is preferred
if column.to_s == "prodid"
proHash = Hash.new { |h, k| h[k] = [ ] }
proHash['relid'] << row[:relid]
proHash['releasename'] << row[:releasename]
proHash['inheritcomponents'] << row[:inheritcomponents]
# to_i is preferred
productId = value.to_i
# this notation is preferred
result[productId] ||= []
# this is identical to what you did and more readable
result[productId] << proHash
end
end
end
$log.info("Method #{self.class.name}.#{__method__} has finished")
#productReleaseArr = result
end

Answer 2

You haven't given much to go on, but it appears that #releaseHashTable contains an Array, not a Hash.
Update: Based on the implementation you posted, you can see that productId is an integer and that the return value of readReleaseCSV() is an array.
In order to get the releasename you want, you have to do this:
#releaseHashTable[productId][n][:releasename]
where productId and n are integers. Either you'll have to specify them specifically, or (if you don't know n) you'll have to introduce a loop to collect all the releasenames for all the products of a particular productId.

Answer 3

This is what Mark Thomas meant:
> a = [1,2,3] # => [1, 2, 3]
> a[:sym]
TypeError: can't convert Symbol into Integer
# here starts the backstrace
from (irb):2:in `[]'
from (irb):2
An Array is only accessible by an index like so a[1] this fetches the second element from the array
Your return a an array and thats why your code fails:
#....
result = Array.new
#....
#productReleaseArr = result
# and then later on you call
#releaseHashTable = readReleaseCSV()
#releaseHashTable[:releasename] # which gives you TypeError: can't convert Symbol into Integer