You may use the different accessors to communicate your intent to someone reading your code, and make it easier to write classes which will work correctly no matter how their public API is called. Here, I can see that I may both read and write the age. Here, I can see that I may only … Read more
Open your terminal and run When this is complete, you need to restart your terminal for the rvm command to work. Now, run rvm list known This shows the list of versions of the ruby. Now, run rvm install ruby@latest to get the latest ruby version. If you type ruby -v in the terminal, you should see ruby X.X.X. If it still shows you ruby 2.0., … Read more
There are pieces to this answer that helped me get what I needed (easy multi-line concatenation WITHOUT extra whitespace), but since none of the actual answers had it, I’m compiling them here: As a bonus, here’s a version using funny HEREDOC syntax (via this link): The latter would mostly be for situations that required more flexibility … Read more
Functions that end with ? in Ruby are functions that only return a boolean, that is, true, or false. When you write a function that can only return true or false, you should end the function name with a question mark. The example you gave shows a ternary statement, which is a one-line if-statement. .nil? is a boolean … Read more
Note: While this answer has the desired effect, it does so by reducing overall security. The below answer by Alon is more correct and maintains the security of the site.
Like this: The num_secs value can be an integer or float. Also, if you’re writing this within a Rails app, or have included the ActiveSupport library in your project, you can construct longer intervals using the following convenience syntax:
This looks like JavaScript Object Notation (JSON). You can parse JSON that resides in some variable, e.g. json_string, like so: If you’re using an older Ruby, you may need to install the json gem. There are also other implementations of JSON for Ruby that may fit some use-cases better: YAJL C Bindings for Ruby JSON::Stream
Ruby uses the case expression instead. Ruby compares the object in the when clause with the object in the case clause using the === operator. For example, 1..5 === x, and not x === 1..5. This allows for sophisticated when clauses as seen above. Ranges, classes and all sorts of things can be tested for rather than just equality. Unlike switch statements in many other languages, Ruby’s case does not have fall-through, so … Read more
The map method takes an enumerable object and a block, and runs the block for each element, outputting each returned value from the block (the original object is unchanged unless you use map!): Array and Range are enumerable types. map with a block returns an Array. map! mutates the original array. Where is this helpful, and what is the difference between map! and each? Here is an example: … Read more
Localhost means quite literally “your local host”, usually identified by 127.0.0.1 and all traffic to that address is routed via a loopback interface. If your Web server is listening for connections on 127.0.0.1, this means that it only accepts requests coming from the same host. 0.0.0.0 means that Rails is listening on all interfaces, not just the … Read more