ArgumentError: wrong number of arguments (given 0, expected 1).
The code opens the file and looks at the paragraph and counts, the error
is in the center of the code. An error occurs when a method is called(1).
I can’t understand how to pass the argument methods.
#books = "You can use this knowledge to create small tools that might help."
require "colorize"
class Filecalculation
def select
loop do
puts "# Will we search : calculation_lines paragraph(1)".cyan
print "\n>>>>>> ".yellow
input = gets.chomp
search_method = "calc_#{input}"
if (respond_to?(search_method))
I can’t understand how to pass the argument to this place.
contents = send(search_method, #books)
else
puts "Unknown input: #{input.inspect}, method #{search_method} not defined."
end
end
end
# =================== calc_1 сounting words in Text File
def calc_1 paragraph
word_count = paragraph.split.length
puts "#{word_count} words"
end
end
Filecalculation.new.select
If you call send(search_method) you call a method without arguments. To pass arguments to the method being called, you need to pass them as next send args:
send(search_method, arg1, arg2)
in your case
send(search_method, paragraph)
Docs
Related
I know writing like
a=23
p "the value of a is #{a}"
it will print: the value of a is 23.
but now I am actually receiving this string as a parameter like
def evaluate string
a=23
puts string
end
calling method pass that string as a parameter
evaluate "the value of a is #{a}"
Is there any way to evaluate this string inside the method? puts string has to interpolate the value a=23.
Edit:
I have to read and execute the program from Excel.
At the first line,
Excel entry is,
"id=something" setvalue a
So now corresponding program will read the value from locator id=something and set it into the instance variable #a.
and user's next excel entry would be
"the value of a is 23" compare "the value of a is #{a}"
Now the program will read "the value of a is 23" and this "the value of a is #{a}" for comparison, but before it compares, it has to replace the value a. That's all I want. I hope now my question is very clear.
For ruby you can change how you "format" your strings in Excel, than you can use "classic" formatting
a = 23
s = 'the value of a is %s'
def evaluate(text, value)
puts text % value
end
You can use different formatting keys, for example %d for integers, %f for float numbers
You can use named arguments
dynamic_text = 'the value of the %<product_name>s is %<product_price>0.2f'
def evaluate(text, args)
puts text % args
end
name = "Product"
price = 78.99
evaluate dynamic_text, product_name: name, product_price: price
Without names, use order of the given values
dynamic_text = 'the value of the %s is %0.2f'
def evaluate(text, args)
puts text % args
end
name = "Product"
price = 78.99
evaluate dynamic_text, [name, price]
You can make a block and then evaluate the string:
def evaluate &block
a=23
block.call(a)
end
evaluate { |a| "the value of a is #{a}" } #=> "the value of a is 23"
It's a very odd thing you're attempting to do. When you have some sort of a pattern with placeholders, you do it like:
def evaluate(string)
a=23
format string, a: a
end
evaluate "the value of a is %{a}"
String interpolation with #{..} is not meant for the case you're describing as the value is evaluated at the time of constructing the string, not later. You could do some regexp matching and replace the #{..} with %{..} as a workaround.
There's a few ways:
"Code" Dynamic
lazy evaluation with lambdas:
def evaluate(str_template)
a = 23
str_template.call(a)
end
user_input = gets
my_lambda = lambda do |str|
user_input.size > 10 ? "dynamic 1 #{str}" : "dynamic 2 #{str}"
end
evaluate(my_lambda)
# => "dynamic 1/2 23"
This is "code dynamic", but not "input dynamic", i.e. you can't receive the string template from the user.
"Input" Dynamic 1
ERB templating:
require 'erb'
user_input_erb = gets
puts user_input_erb # "Hello <%= name %>"
name = gets # also user input, e.g. "World"
ERB.new(user_input_erb).result
# => "Hello World"
Note that in general, getting string templates from the user and evaluating them is a potential security vulnerability. If there's any possibility user input can be adversarial, you'll want to see if you can find a "guaranteed to be safe against all user input" string templating library.
"Input" Dynamic 2
user_input_template = gets
puts user_input_template # "Hello %s"
name = gets # also user input, e.g. "World"
user_input_template % name
# => "Hello World"
"Input" Dynamic 3
Really dangerous, but:
user_input_ruby_code = gets
puts user_input_ruby_code # '"Hello #{name}"'
name = gets # also user input, e.g. "World"
eval user_input_ruby_code # DANGER
# => "Hello World"
class LineAnalyzer
##highest_wf_count=[]
##highest_wf_words=[]
attr_accessor :highest_wf_count ,:highest_wf_words ,:content , :line_number
def initialize(line,num)
#content=line
#line_number=num
calculate_word_frequency(#content,#line_number).call
end
def calculate_word_frequency(con,num)
#content,#line_number=con,num
#arr= #content.split()
#arr.map do |txt|
#count=0
#i=0
while #i<#content.length
#count+=1 if txt.eql?(#arr[#i])
#i+=1
end
##highest_wf_count[#line_number]= #count
##highest_wf_words[#line_number]= txt
#arr.delete(txt)
end
end
end
class Solution < LineAnalyzer
attr_accessor :analyzers, :highest_count_across_lines, :highest_count_words_across_lines
def initialize
#analyzer=[]
#highest_count_across_lines=0
#highest_count_words_across_lines=[]
end
def analyze_file()
#arr=IO.readlines(ARGV[0])
#analyzers=Array.new(#arr.length){LineAnalyzer.new}
#i=0
#analyzer.each do |obj|
obj(#arr[#i],#i)
#i+=1
end
end
def calculate_line_with_highest_frequency()
#highest_count_across_lines = ##higest_wf_count.max
#i=0
##highest_wf_count.each do |count|
#highest_count_words_across_lines.push ##highest_wf_words[#i] if count==#highest_count_across_lines
#i+=1
end
end
The above code is to calculate word frequency in a text file
Whenever I try to run this below command I get the following error int the intialize function in LineAnalyzer class
ruby module2_assignment.rb test.txt
Error : `initialize': wrong number of arguments (given 0, expected 2) (ArgumentError)
Since I am a beginner in Ruby I can't figure out the error.
The issue is in this line
#analyzers=Array.new(#arr.length){LineAnalyzer.new}
LineAnalyzer's constructor requires two parameters, you're passing none
well, the issue of initialize: wrong number of arguments can be resolved in passed arguments into LineAnalyzer.new, but we still have broken script after those changes, so, as I see, this script in [WIP] status, and we need to make some more changes to make it works.
If you can share more details about the goal of analyzing here, it would be nice.
so, go to code, we need to remove call from this line:
calculate_word_frequency(#content,#line_number)
and fix initializer logic here:
def initialize
#analyzers=[]
#highest_count_across_lines=0
#highest_count_words_across_lines=[]
end
def analyze_file()
#arr=IO.readlines(ARGV[0])
#i=0
#arr.each do |line|
#analyzers << LineAnalyzer.new(line,#i)
#i+=1
end
end
btw you have a typo in this line:
#highest_count_across_lines = ##higest_wf_count.max
should be:
#highest_count_across_lines = ##highest_wf_count.max
so, we've resolved issue, but it still not good, coz output is nothing:
ruby module2_assignment.rb test.txt
Test text
Test text
Test text
1
1
1
coz should be something like this:
module2_assignment.rb test.txt
1
2
3
"The following words have the highest word frequency per line: "
"[\"test\", \"text\"] (appears in line 1)"
"[\"test\", \"text\"] (appears in line 2)"
"[\"test\", \"text\"] (appears in line 3)"
So, I think we have 2 options here:
invest some more efforts to make it works
try to find a similar solution
we can use this worked solution of module2_assignment, for example:
https://github.com/zbristor/rubyWordFrequency/blob/2417324381378f6be76485f6271465cd641ec0ff/module2_assignment.rb
I hope it's help
I'm trying to get an if statement for users who put incorrect data.
Here's my code:
class Breweries::CLI
def start
puts "Hello!"
puts "---------------------------"
puts "Please enter your location:"
input = gets.strip.downcase
#data = Breweries::API.get_breweries(input)
#objects = Breweries::HoppyCode.all
if input.length < 1
puts "Sorry!!"
puts "```````"
start
else
display_info
end
end
def display_info
puts "You'll love the following spots!"
puts "********************************"
#objects.each.with_index(1) {|brewery, index| puts "#{index}. #{brewery.name}"}
puts "Please make a selection by index number for more information:"
input = gets.strip.downcase
if(input.to_i > 0)
#brewery = #objects[input.to_i - 1]
puts "name: #{#brewery.name}"
puts "street: #{#brewery.street}"
puts "city: #{#brewery.city}"
puts "phone: #{#brewery.phone}"
puts "website_url: #{#brewery.website_url}"
display_info
elsif (input == "quit")
quit
elsif (input == "menu")
start
end
end
def quit
puts "Goodbye. Drink responsibly and enjoy."
end
end
When I put something that would generate an error, it returns the following:
Please enter your location: nvifpejvf80ejvip
Traceback (most recent call last):
2: from bin/breweriesCLI:6:in `<main>'
1: from /home/munificent-format-5297/Development/breweries/lib/breweries/cli.rb:8:in `start' /home/munificent-format-5297/Development/breweries/lib/breweries/api.rb:6:in `get_breweries': undefined method `[]' for nil:NilClass (NoMethodError)
How can I solve the undefined method '[]' error? Here's the API code in case that's necessary.
class Breweries::API
def self.get_breweries(input)
#breweries_hash = HTTParty.get("https://api.openbrewerydb.org/breweries?by_city=#{input}")
breweries_obj = {
name: #breweries_hash[1]["name"],
street: #breweries_hash[3]["street"],
city: #breweries_hash[4]["city"],
phone: #breweries_hash[10]["phone"],
website_url: #breweries_hash[11]["website_url"]
}
Breweries::HoppyCode.new(breweries_obj)
end
end
When the input is invalid, the call to
#breweries_hash = HTTParty.get("...")
returns not the object you expect (I’d suggest it returns an empty hash.) That makes it impossible to get to details in the following lines. Depending on how are you to handle it, you might decide to e. g. early return from this function, or raise, or do something else.
To approach this, start with debugging the issue, like this:
#breweries_hash = HTTParty.get("...")
puts #breweries_hash.inspect
...
That way you’ll see what gets returned and get the ideas of how to handle it.
If I am right, and what is returned is an empty hash, you might want to early return from this function.
#breweries_hash = HTTParty.get("...")
return if #breweries_hash.empty?
...
Identifying the Problem
There are lots of ways to solve for the nil problem, but at a quick glance it seems like part of the problem here is that you're somehow expecting input to return a valid Hash object from your API call, but an empty String or an instance of FalseClass may not do that. Consider the following:
input = gets.strip.downcase # <RETURN> here gets an empty string
input #=> ""
input.to_i > 0 #=> false
Then consider that some downstream of Breweries::API.get_breweries is expecting to operate on a Hash object instead if an instance of NilClass. In this case, that looks like #breweries_hash[1]["name"] and other operations on #breweries_hash.
Some Options
Without knowing more about your code, I don't want to be prescriptive here. But in general, you can do one or more of the following:
Coerce arguments into the expected class in the method call, the method signature, or the method body. For example, for Array objects:
# coerce a String to an Array, raising an exception if it can't
input = ""
Array(input)
#=> [""]
# coerce some Array to a Hash
array = [:name, "foo", :street, "bar"]
Array(array.each_slice 2).to_h
#=> {:name=>"foo", :street=>"bar"}
Explicitly check that you have an Hash object:
fail "#breweries is not a Hash" unless #breweries.is_a? Hash
Raise an exception rather than return 0 if input isn't actually a valid Integer representation in the first place:
input = Integer(gets.strip.downcase)
Check if your Hash or Array object responds to the relevant method calls, and raise a more helpful exception message:
raise sprintf("#brewery: %s", #brewery.class) unless #brewery.respond_to? :[]
There are other things you might do as well. Broadly speaking, you need to adjust your code to check the return value of your call to ensure it's not nil, then branch/raise/rescue appropriately depending on whether or not you ever expect nils as a valid return value from Breweries::API.get_breweries.
A Note on Using Exceptions for Non-Exceptional Circumstances
As a rule of thumb, you should only raise exceptions for truly unexpected circumstances, or when the program should halt because some condition can't (or shouldn't) be handled within the program during runtime. Which is best in your particular use case is really a design decision, and outside the scope of the original question. However, you might want to read Avdi Grimm's Exceptional Ruby for a deeper explanation of when exceptions might better than branching or handlers (or vice versa), but the choice in your code is a little left of center of the problem you're actually dealing with right now.
This is a small test script I wrote:
#!/usr/bin/env ruby
require 'packetfu'
def mac(host)
if host
rmac = PacketFu::Utils.arp(host, :iface => 'wlan0')
puts rmac
else
whoami = PacketFu::Utils.whoami?(:iface => 'wlan0')
puts whoami
end
end
mac(ARGV[0])
What I want to do is have it print the second variable if no argument is specified. Instead I get an ArgumentError. There's obviously an easier way that I'm just missing.
If you want to be able to call the function without any arguments, you need to change its definition to such that it does not require an argument. One way is to give the argument a default value. Then you can check for that, e.g.,
def mac(host = nil)
if host
puts "host: #{host}"
else
puts 'no host'
end
end
If you want to distinguish between no argument given and argument given with the default value, you could use a variable number of arguments:
def mac2(*args)
if args.empty?
puts "no arguments"
else
host = args[0]
end
end
On the other hand, if your problem is detecting whether ARGV was empty (i.e., no command-line argument given), you can check that higher up. For example, only call mac if an argument was given:
if ARGV.empty?
puts "Usage: …"
exit 1
end
mac(ARGV[0])
I am attempting to learn Ruby by converting a Java program to Ruby, but I've been coming up with an error surrounding this block of code:
def create
#user_input = String.new()
# #word_arr = Array.new
print "Enter the text to be converted to pig latin, EOF to quit: "
while gets do
STDOUT.flush
#user_input = gets.chomp
#word_arr = #user_input.string.split(' ')
#word_arr.each { |x| puts x.engToLatin() + ' '}
print "EOF to Quit"
#user_input = ""
end
end
I've been getting this error:
EnglishToPigLatin.rb:14:in `create': private method `chomp' called for nil:NilClass (NoMethodError)
from EnglishToPigLatin.rb:60
This is the area around line 60:
#if __FILE__ == $0
mg = EnglishToPigLatin.new
mg.create
#end
Essentially what I am trying to do is while there is still input, get that input, split it up into individual words, and run each word through a Pig Latin conversion method.
It looks like you're trying to get input inside of your loop.
Try
loop do
user_input = gets.chomp!
word_arr = user_input.to_s.split(' ')
word_arr.each { |x| puts x.engToLatin() + ' '}
puts "EOF to Quit"
end
Otherwise you're trying to get the next line of input when there isn't one. Additionally, do isn't necessary for a while statement.
You also don't need to reset #user_input to ''.
And since this is all in a block, you don't need to use instance variables, unless the methods you call need them.
Also your conditional is always true. gets will block until it gets a line of input. You can use loop for an infinite loop that ends on an interrupt.
Also, you needn't flush STDOUT if you use a puts for the last line there instead of a print.
The whole thing could be a script or a method in a module. An instance doesn't even need to be made. And if you do, instead of using two lines with your mg.create, you should define an initialize method. This is used as a constructor then, and whatever you set when you create an instance should be put there.
It can all be done like this:
loop do
puts gets.chomp.split(' ').map{ |x| x.engToLatin() }.join(' ')
puts "EOF to Quit"
end
Mario's answer is right. But I have the following notes.
You can still use the while construction as below.
+' ' implies that you don't want line breaks after each word. I changed that part. map and join is common in similar cases. print does not add a line break while puts does.
I am not sure what you are trying to do with STDOUT.flush. If you wanted to scroll to the top of the screen before each output, use system('clear').
You have a method entToLatin, and it should work, but it is a ruby convention to use underscore, like eng_to_latin for methods (although there are a few exceptions).
So a more rubyish way would be:
def create
print "Enter the text to be converted to pig latin, EOF to quit: "
while input = gets.strip and input != 'EOF'
system('clear')
puts input.split(/\s+/).map{|x| x.engToLatin}.join(' ')
puts "EOP to Quit"
end
end
And if you are using ruby 1.9.2, you can shorten map so that:
def create
print "Enter the text to be converted to pig latin, EOF to quit: "
while input = gets.strip and input != 'EOF'
system('clear')
puts input.split(/\s+/).map(:engToLatin).join(' ')
puts "EOP to Quit"
end
end