Array#Difference - Array#Difference

I wanted to do a quick post on a new method added to ruby Array class in version 2.6. I just learned about this over the past weekend. This will quickly grow to be a favorite of mine.

A method to check differences in values between two arrays.

Make arrays abc and abcdef

[1] pry(main)> abc = ['a','b','c'] 
=> ["a", "b", "c"]

[2] pry(main)> abcdef = ['a', 'b', 'c', 'd', 'e', 'f']
=> ["a", "b", "c", "d", "e", "f"]

Ruby 2.5

In versions prior, I would make a .difference method in my .pryrc file and that will be loaded at runtime when I run my console. You can also monkey patch it live in a pry console. Found this via stackedoverflow post. Here is how I would add it in a running pry session:

[17] pry(main)> class Array
[17] pry(main)*   def difference(a)
[17] pry(main)*     self - a | a - self
[17] pry(main)*   end  
[17] pry(main)* end  
=> :difference

[26] pry(main)> abcdef.difference(abc)
=> ["d", "e", "f"]

Ruby 2.6

But now in ruby 2.6+, you can just use the .difference method. It is built into the class now.

[3] pry(main)> abcdef.difference(abc)
=> ["d", "e", "f"]

So nice, so easy!