Programs that require multiple threads of execution are a perfect candidate for ruby s thread class.
Ruby set variable if not nil.
Def fetch it baby many items nil obj items per p.
In ruby on rails what s the difference actually.
Just like any other ruby object nil has a set of methods.
Always remember in ruby true false and nil are objects not numbers whenever ruby requires a boolean value then nil behaves like false and values other than nil or false behave like true.
What about instance variables.
This is a hybrid of array s intuitive inter operation facilities and hash s fast lookup.
An enumerable object can be converted to set using the to set.
Set is easy to use with enumerable objects implementing each most of the initializer methods and binary operators accept generic enumerable objects besides sets and arrays.
Threads are the ruby implementation for a concurrent programming model.
I have obj items per page which is 20 at the beginning and i want the method below to assign value to it only if many items is not nil.
Set implements a collection of unordered values with no duplicates.
For many beginning rubyists especially those having experience in other programming languages such as java or c checking whether variable is nil may seem a little bit confusing.
You should be aware that undefined instance variables will return nil.
Then we are able to pause the execution of the main thread and allow our new.
Ruby is an open sourced object oriented programming language developed by yukihiro matsumoto in ruby everything is treated as an object.
September 11 2010 4 minute read tags.
Memoirs of a software team leader read more.
Try the safe navigator operator ruby 2 3 which only calls a method if the variable is not nil.
Not only is if variable nil.
For example we can create a new thread separate from the main thread s execution using new.
True false and nil are built in data types of ruby.
New puts what s the big deal.
Read more like natural language it also guards against a programmer accidentally assigning it a false value and falling into your if statement since ruby is a loosely typed language.
Foo nil so watch out for that it might just happen that you misspelt the name of your instance variable or you forgot to initialize it.
And even those speaking ruby quite fluently don t usually know the tiny little details.
There are plenty of options available.
