Spoiler alert: I am a true novice. Tasked with figuring out fizz buzz in ruby for a class and while I have found more than a few versions of code that solve the problem, my understanding is so rudimentary that I cannot figure out how these examples truly work. First question(refer to spoiler alert if … Read more
db:migrate runs (single) migrations that have not run yet. db:create creates the database db:drop deletes the database db:schema:load creates tables and columns within the existing database following schema.rb. This will delete existing data. db:setup does db:create, db:schema:load, db:seed db:reset does db:drop, db:setup db:migrate:reset does db:drop, db:create, db:migrate Typically, you would use db:migrate after having made changes to the schema via new migration … Read more
A variable prefixed with @ is an instance variable, while one prefixed with @@ is a class variable. Check out the following example; its output is in the comments at the end of the puts lines: You can see that @@shared is shared between the classes; setting the value in an instance of one changes the value for all other instances of that class and … Read more
The proper way to determine the “type” of an object, which is a wobbly term in the Ruby world, is to call object.class. Since classes can inherit from other classes, if you want to determine if an object is “of a particular type” you might call object.is_a?(ClassName) to see if object is of type ClassName or derived from it. Normally type checking … Read more
p foo prints foo.inspect followed by a newline, i.e. it prints the value of inspect instead of to_s, which is more suitable for debugging (because you can e.g. tell the difference between 1, “1” and “2\b1”, which you can’t when printing without inspect).
What is wrong with Date.parse method? It seems to work. The only problem here is time zone. If you want date in UTC time zone, then it is better to use Time object, suppose we have string: I couldn’t find simpler method to convert Time to Date.
“pop”ing the first element of an Array is called “shift” (“unshift” being the operation of adding one element in front of the array).
Use “\n” instead of ‘\n’
Bundle with Ruby 2.1.6 You just need to install bundler : This will be installed in a gemset specific to ruby-2.1.6, so it won’t interfere with anything you installed with ruby-2.3.0. You can use to install the required gems. Trying with Ruby 2.3.0 Alternatively, you could just try the example you downloaded with ruby-2.3.0 by … Read more
kind_of? and is_a? are synonymous. instance_of? is different from the other two in that it only returns true if the object is an instance of that exact class, not a subclass. Example: “hello”.is_a? Object and “hello”.kind_of? Object return true because “hello” is a String and String is a subclass of Object. However “hello”.instance_of? Object returns … Read more