How do I write a function's return to a file?

Question

I created a name generator.

When I try to save the results to a file it either enters a blank line or it says "true". I need it to put and say the generated name in the file.

Here's my code:

def generate_secondname
  dice = rand
  if dice > 0.01 && dice < 0.09
    print "saunders"
  elsif dice > 0.10 && dice < 0.19
    print "winters"
  elsif dice > 0.20 && dice < 0.29
    print "burgess"
  elsif dice > 0.30 && dice < 0.39
    print "webster"
  elsif dice > 0.40 && dice < 0.49
    print "holister"
  elsif dice > 0.50 && dice < 0.59
    print "johnson"
  elsif dice > 0.60 && dice < 0.69
    print "green"
  elsif dice > 0.70 && dice < 0.79
    print "paul"
  elsif dice > 0.80 && dice < 0.89
    print "hendrix"
  else dice > 0.90 && dice < 0.99
  print "luster"
  end
end


def generate_name(generate_secondname)
  dice = rand
  if (dice >= 0.01) && (dice <= 0.09)
    print "ashley"
    print "#{generate_secondname}"
  elsif dice > 0.10 && dice < 0.19
    print "george"
    print "#{generate_secondname}"
  elsif dice > 0.20 && dice < 0.29
    print "nick"
    print "#{generate_secondname}"
  elsif dice > 0.30 && dice < 0.39
    print "sam"
    print "#{generate_secondname}"
  elsif dice > 0.40 && dice < 0.49
    print "roland"
    print "#{generate_secondname}"
  elsif dice > 0.50 && dice < 0.59
    print "preston"
    print "#{generate_secondname}"
  elsif dice > 0.60 && dice < 0.69
    print "brandon"
    print "#{generate_secondname}"
  elsif dice > 0.70 && dice < 0.79
    print "sean"
    print "#{generate_secondname}"
  elsif dice > 0.80 && dice < 0.89
    print "ysabel"
    print "#{generate_secondname}"
  else dice > 0.90 && dice < 0.99
  print "patricia"
  print "#{generate_secondname}"
  end
end

file1 = File.new("randomname.txt", "a")

arr1 = []

name = generate_name(generate_secondname).to_s

file1.puts name.to_s

I tried putting the results into an array and then using:

arr1 << name
file.puts arr1

but it didn't work.

I also tried using hashes like:

file.puts "#{generate_name(generate_secondname)}"

which didn't work.

Inside the functions are just the rand method and a bunch of if/else statements with name strings.

Answer 1

Ruby makes it really easy to open a file for appending, write to it and close it. The idiomatic way to do so is:

File.open('randomname.txt', 'a') do |fa|
  fa.puts 'foo'
end

We use the block form because Ruby will automatically close the file as soon as the block exists. That makes our code very clean.

A file opened for appending is just a series of bytes as far as Ruby is concerned. Basically the current file position is set to the end of the file before writing occurs, effectively appending. Nothing else is needed as far as our code is concerned.

Save the code above and run it twice and then look at "randomname.txt" and it will contain

foo
foo

When I try to save the results to a file it either enters a blank line or it says "true".

Then the problem exists elsewhere, not in the I/O section. You don't show us what is in

name = generate_name(generate_secondname).to_s

so it's impossible to debug your black box. Using basic debugging skills, you should break the problem into the smallest steps possible, and prove/disprove whether they are working. That's what the code above does, it proves that appending a fixed string works.

The second step would be to introduce your method which is supposed to generate the string being output. If the string output to the file is wrong then you immediately know the method is wrong, so begin testing there. Or, reverse the process and write code to test only your method, then test it surrounded by the File.open block. Either way, reduce the problem to its smallest steps.

---

(added after code was added to the question)

Back to your code...

else doesn't take a comparison or code, it only is else, so don't use this:

else dice > 0.90 && dice < 0.99

Instead use:

else

Your code also has some logic errors. rand returns a Float, and your code isn't adequately handling the value ranges possible. Consider this:

rand # => 0.5082475113018177

rand doesn't return a number rounded to 100ths, so its precision is going to squeeze through holes in your conditions:

dice = 0.091
if (dice >= 0.01) && (dice <= 0.09)
  puts "ashley"
elsif dice > 0.10 && dice < 0.19
  puts "george"
# elsif dice > 0.20 && dice < 0.29
#   puts "nick"
# elsif dice > 0.30 && dice < 0.39
#   puts "sam"
# elsif dice > 0.40 && dice < 0.49
#   puts "roland"
# elsif dice > 0.50 && dice < 0.59
#   puts "preston"
# elsif dice > 0.60 && dice < 0.69
#   puts "brandon"
# elsif dice > 0.70 && dice < 0.79
#   puts "sean"
# elsif dice > 0.80 && dice < 0.89
#   puts "ysabel"
else dice > 0.90 && dice < 0.99
  puts "patricia"
end
# >> patricia

dice is larger than 0.09 but less than 0.1, so there's your hole in action. The logic will fall through and hit the else any time the value doesn't match a range you want. (Of course that might be the desired result but you'd have to document that in the code and hope someone doesn't come along later and "fix" the problem because it's highly unintuitive to do it that way.)

Instead you need to close those holes. I'd do it using something like:

dice = 0.091
name = case 
       when dice >= 0.90
         "patricia"
       when dice >= 0.80
         "ysabel"
       when dice >= 0.70
         "sean"
       when dice >= 0.60
         "brandon"
       when dice >= 0.50
         "preston"
       when dice >= 0.40
         "roland"
       when dice >= 0.30
         "sam"
       when dice >= 0.20
         "nick"
       when dice >= 0.10 
         "george"
       else 
         "ashley"
       end
puts name
# >> ashley

By reversing the order of the tests I don't need to set the top boundary for the tests, and I don't have a problem with gaps. It's also a LOT easier to read.

Finally, don't do this:

"#{generate_second_name}"

It's wasting CPU time. generate_second_name already returns a string, so you're stringifying a string:

def generate_second_name()
  'foo'
end
generate_second_name.class # => String
"#{generate_second_name}".class # => String

Instead, use the bare generate_second_name instead.

Answer 2

You need to break the problem into smaller pieces. First check whether you can write to a file at all. Make sure you don't have the files you're trying to write to already open with an editor.

begin
  file = File.open("/tmp/some_file", "w")
  file.write("your text") 
rescue IOError => e
  #some error occur, dir not writable etc.
ensure
  file.close unless file == nil
end

If that correctly writes "your text" then swap out the "your text" for your generate_name result. Next, you can change the location the file is being opened at. Assuming it still works you have eliminated the possibility that it was caused by a permissions issue. Lastly, try removing the file.close part to see if you can reproduce the same issue.

EDIT:

Upon looking at your generate_secondname method, I believe to fix your issue you simply need to change every instance of the word print to return.

For example:

...
if dice > 0.01 && dice < 0.09
    return "saunders" # you must return the strings, NOT print them
elsif dice > 0.10 && dice < 0.19
...

For generate_name you'll need to combine your strings before returning them. For example:

...
if (dice >= 0.01) && (dice <= 0.09)
  return "ashley #{generate_secondname}" # see how this is now 1 line, instead of 2
elsif dice > 0.10 && dice < 0.19
...