Ruby Reference

Contents

• Documentation
• FAQ
  • How do I run a specific version of a gem?
  • What is the RubyGems error ... is not an octal string related to?
• ruby-study
  • .ruby-version
  • core/hash/delete.rb
  • core/hash/dig.rb
  • core/hash/transform_keys.rb
  • core/hash/transform_values.rb
  • core/io/read.rb
  • core/io/readlines.rb
  • core/string.rb
  • std-lib/set.rb

Documentation

• Official Core Library Documentation (latest stable ruby version)
• Official Standard Library Documentation (latest stable ruby version)
• Official Downloads, including information on release status

FAQ

How do I run a specific version of a gem?

$ my-gem _x.y.x_ [args]

What is the RubyGems error ... is not an octal string related to?

AKA: “Why am I getting ... is not an octal string when running gem push?”

I encountered this when I was incorrectly pushing the .gemspec, rather than the .gem.

When publishing to RubyGems you should:

$ cd path/to/my-gem
$ gem build my-gem
$ gem push my-gem-0.0.1.gem

ruby-study

.ruby-version

3.1.3~~~~~~~~~~

### README.md

~~~~~~~~~~markdown
# ruby-study

Personal study area for the latest version of [ruby](https://www.ruby-lang.org/en/).

core/hash/delete.rb

# hash delete key
h = {a: 1, b: 2}
h.delete(:a)

core/hash/dig.rb

# hash find within nested object
h = {foo: { bar: { baz: -1}}}
h.dig(:foo)
h.dig(:foo, :bar)
h.dig(:foo, :bar, :baz)
h.dig(:foo, :qux)

core/hash/transform_keys.rb

# hash convert symbol keys to strings
h = {foo: "bar"}
h_transformed = h.transform_keys {|k| k.to_string }

# perform transform keys in-place
h.transform_keys! {|k| k.to_string }

core/hash/transform_values.rb

# hash transform values
h = {a: 1, b: 2}.transform_values {|v| v * v }

# perform transform values in-place
h.transform_values! {|v| v * v }

core/io/read.rb

# read file as string
contents = IO.read('path/to/file.txt')

core/io/readlines.rb

# read lines of file, using `chomp: true` to omit newlines
lines = IO.readlines('path/to/file.txt', chomp: true)

core/string.rb

# strip (trim)
s1 = "  foo\n ".strip

# strip! (trim)
input1 = "  foo\n "
input1.strip!

std-lib/set.rb

require 'set'

s1 = Set[1,2]
s2 = [1,2].to_set