CODEWITHSUNDEEP
ruby-on-railsruby
tokhi
tokhi

Reputation: 21616

undefined method `gsub' for nil:NilClass (NoMethodError

I have the below code snippet:

   line_sub = Regexp.new(/\s+|"|\[|\]/)
   tmp = Array.new
    # reading a file
   while line = file.gets
     ... 
     tmp[0],tmp[1] = line.to_s.scan(/^.*$/).to_s.split('=')
    #remove unwanted characters
     tmp.collect! do |val|
       val.gsub(line_sub, "")
     end
    ...
   end

but when I run the code I get the error:

 undefined method `gsub' for nil:NilClass (NoMethodError)

something seems to be wrong here:

tmp.collect! do |val|
 val.gsub(line_sub, "")
end

Any idea?

Upvotes: 2

Views: 17152

Answers (5)

brentmc79
brentmc79

Reputation: 2541

If there should always be a value on each side of the "=" in the line, like "foo=bar" and not "foo=", then try something like this:

line.match(/(.+)=(.+)/ do |match|
  # do whatever you need with the match
  # if there is no match this block won't be executed
  tmp = match[1..2]
  tmp.map! do |string|
    string.gsub(/[\s"\[\]/, "")
  end
end

Upvotes: 0

vijikumar
vijikumar

Reputation: 1815

Add one condition like this

     tmp.collect! do |val|
        if !val.nil?
           val.gsub(line_sub, "")
        end
     end

Upvotes: 2

Dipak Panchal
Dipak Panchal

Reputation: 6036

try this way for your solution

tmp.collect! do |val|
  if val.present?   # or unless val.nil?
    val.gsub(line_sub, "")
  end
end

Upvotes: 6

oldergod
oldergod

Reputation: 15010

One of the line you are reading is either empty, or it does not contain a '=' character.

#Then, you get either
tmp[0], tmp[1] = ["only one element"]
# => tmp[1] = nil

#or
tmp[0], tmp[1] = []
# both are nil.

Upvotes: 1

sawa
sawa

Reputation: 168199

It means tmp[0] and/or tmp[1] is nil. Your

line.to_s.scan(/^.*$/).to_s.split('=')

didn't work as intended. Better check the result of that part.

By the way, line.to_s.scan(/^.*$/).to_s does not make sense. If you want to work on each line of the file, do

file.each_line do |l|
  ...
  l ...
end

Upvotes: 1

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