4 ms·

Regarding copy/pasting, I do agree. Not much of a point in reading if you're just going to do that. But, I was having a problem with exercise 4 and so copy/pas

Regarding copy/pasting, I do agree. Not much of a point in reading if you're just going to do that. But, I was having a problem with exercise 4 and so copy/pasted it from the webpage (removed line numbers with TextMate's vertical selection easily enough). Received the same error when trying to run it as I did when I typed it myself: ex4.rb:10:in `+': can't convert Fixnum into String (TypeError) from ex4.rb:10:in `<main>' I'm not familiar enough with Ruby to understand why it's doing that... my googling shows similar ruby tutorials with that format, but one site I found suggested using #{variable_name} instead of the " + variable_name + " and that worked just fine for me. Is this a real error in the book or something weird going on with my computer (OS X Lion w/ Ruby 1.9.2 installed)? Great book, by the way.

GaltMidas 15y ago
Couldn't get your way to work, it blew off the rest of the string. Managed to get it to work by calling .to_s on each variable. Wondering if I did something wrong. I have your same setup and I'm a complete Ruby Noob.
- reaganing 15y ago
  to be clear, my line 10 looks like this: puts "There are #{cars} cars available." But, yeah, complete Ruby noob here as well so I don't really know what's wrong.
  - danso 15y ago
    >10 puts "There are " + cars + " cars available." Yes, this will throw an error in Ruby because of line 1: >1 cars = 100 Ruby does not allow the mixing of integers and strings. So, as mentioned, you can invoke the .to_s method. Or you can interpolate the variables as you have done so with #{cars} inside double quotes.
    - reaganing 15y ago
      Thank you, that makes sense.
      - getsat 15y ago
        Interpolation actually calls #to_s on the object, so if object.respond_to?(:to_s) returns true, you can use use it inside #{} in any kind of string that allows interpolation.
    - grossvogel 15y ago
      When I read exercise 4, I thought, "I can't believe Ruby made the same mistake as Javascript!" Glad to learn this particular type of foot shooting is not possible in Ruby.
msluyter 15y ago
Also a ruby newb, so I'm not sure, but I think it's an error in the book. I got that error on all versions of ruby I tried. Either var.to_s, or "blah #{var} blah" works for me. This seems to explain it: http://blade.nagaokaut.ac.jp/cgi-bin/scat.rb/ruby/ruby-talk/217432 http://blade.nagaokaut.ac.jp/cgi-bin/scat.rb/ruby/ruby-talk/...
rsobers 15y ago
Ah, I should fix that example. It's totally wrong. Nice catch! In hindsight, I probably should have used "Hello #{name}" style string interpolation in all of the examples since thats the idiomatic way of doing things. I was trying to expose the newcomer to multiple ways of manipulating and concatenating strings, but since the aforementioned way is almost always best, I should stick to that.

GaltMidas 15y ago

Couldn't get your way to work, it blew off the rest of the string. Managed to get it to work by calling .to_s on each variable. Wondering if I did something wrong. I have your same setup and I'm a complete Ruby Noob.

reaganing 15y ago
to be clear, my line 10 looks like this: puts "There are #{cars} cars available." But, yeah, complete Ruby noob here as well so I don't really know what's wrong.
- danso 15y ago
  >10 puts "There are " + cars + " cars available." Yes, this will throw an error in Ruby because of line 1: >1 cars = 100 Ruby does not allow the mixing of integers and strings. So, as mentioned, you can invoke the .to_s method. Or you can interpolate the variables as you have done so with #{cars} inside double quotes.
  - reaganing 15y ago
    Thank you, that makes sense.
    - getsat 15y ago
      Interpolation actually calls #to_s on the object, so if object.respond_to?(:to_s) returns true, you can use use it inside #{} in any kind of string that allows interpolation.
  - grossvogel 15y ago
    When I read exercise 4, I thought, "I can't believe Ruby made the same mistake as Javascript!" Glad to learn this particular type of foot shooting is not possible in Ruby.

msluyter 15y ago

Also a ruby newb, so I'm not sure, but I think it's an error in the book. I got that error on all versions of ruby I tried. Either var.to_s, or "blah #{var} blah" works for me. This seems to explain it: http://blade.nagaokaut.ac.jp/cgi-bin/scat.rb/ruby/ruby-talk/217432 http://blade.nagaokaut.ac.jp/cgi-bin/scat.rb/ruby/ruby-talk/...

rsobers 15y ago

Ah, I should fix that example. It's totally wrong. Nice catch! In hindsight, I probably should have used "Hello #{name}" style string interpolation in all of the examples since thats the idiomatic way of doing things. I was trying to expose the newcomer to multiple ways of manipulating and concatenating strings, but since the aforementioned way is almost always best, I should stick to that.