If you’re using ruby 1.8.7 or 1.9, you can use the fact that iterator methods like each_with_index, when called without a block, return an Enumerator object, which you can call Enumerable methods like map on. So you can do: In 1.8.6 you can do:
It’s a matter of operator precedence. || has a higher precedence than or. So, in between the two you have other operators including ternary (? 🙂 and assignment (=) so which one you choose can affect the outcome of statements. Here’s a ruby operator precedence table. See this question for another example using and/&&. Also, … Read more
undefined method `[]’ for nil:NilClass says you tried to do something[index] but something is nil. Ruby won’t let you use nil as an array (ie. call the [] method on it). The problem is not on the attributs.each line but on the line following which calls the [] method on attribut. This indicates something in … Read more
Its a permissions issue. You could fix it with this: or possibly in your case What does this do: This is telling the system to change the files to change the ownership to the current user. Something must have gotten messed up when something got installed. Usually this is because there are multiple accounts or … Read more
I had a similar problem today with ruby 2.3.3 and rails 4.2.4. The problem was that bundle install of devise installed as a dependency another version of bcrypt (bcrypt (3.1.11 x86-mingw32) instead of bcrypt (3.1.11)) which was causing trouble with ruby 2.3 (it should work with all previous versions of ruby) The solution I used is to install bcrypt … Read more
That’s it. The * is called the splat operator. One caveat per @Mike Lewis (in the comments): “Be very careful with this. Ruby expands splats on the stack. If you do this with a large dataset, expect to blow out your stack.” So, for most general use cases this method is great, but use a different method if you … Read more
153 I believe my answer covers your new concerns about handling any type of line endings since both “\r\n” and “\r” are converted to Linux standard “\n” before parsing the lines. To support the “\r” EOL character along with the regular “\n”, and “\r\n” from Windows, here’s what I would do: Of course this could be a bad idea on very large files since it means … Read more
This question has been discussed so often on the Ruby mailing-lists and Ruby blogs that there are now even threads on the Ruby mailing-list whose only purpose is to collect links to all the other threads on the Ruby mailing-list that discuss this issue. Here’s one: The definitive list of ||= (OR Equal) threads and pages If you really want … Read more
Update the create action as below: You are using respond_to method but anot specifying the format in which a new page is rendered. Hence, the error ActionController::UnknownFormat .
Let’s say you have a class Person. Obviously we never defined method name. Let’s do that. Aha, we can read the name, but that doesn’t mean we can assign the name. Those are two different methods. The former is called reader and latter is called writer. We didn’t create the writer yet so let’s do that. Awesome. Now we can … Read more