Ruby lets you specify default values for a method's arguments---values that will be used if the caller doesn't pass them explicitly. This is done using the assignment operator =.

Nah, the other solution is why people love Ruby:

('10'*size)[0,size]

This solution is why Ruby is the best lang.

Wait, shouldn't you be asking the opposite question, what's the benefit of using "==" over "==="??

Because as everyone knows, you shouldn't be using == except in cases you know it won't get wrong.

because name of method is 'always'

Hi there, I'm not an expert in Ruby, but here you will find a very useful explanation on this matter.

https://blog.newrelic.com/2014/12/10/weird-ruby-2-rescue-interrupt-ensure/

I've hopefully answered your questions. I accidentally posted my reply as a sibling comment.

no 'self ===' it is String method === , '/\A\d\z/ ===' it is Regexp method ===

That is the splat operator - in this context - used for array coercion. You delve deeper here: https://endofline.wordpress.com/2011/01/21/the-strange-ruby-splat/

It's following the functional approach. Think recursively :)

thanks ;)

"the author" doesn't remember this specific kata, but it's quite possible I didn't know how to do something :). Fairly new to ruby.

try this: http://ruby-doc.org/core-2.2.0/String.html#method-i-5B-5D