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authorDavid Hsieh <davidhsiehlo@gmail.com>2016-03-11 08:39:55 -0600
committerDavid Hsieh <davidhsiehlo@gmail.com>2016-03-11 08:39:55 -0600
commitceb99e14019672309ca80350054b7bb1a6642a48 (patch)
tree1cca5af13a146c0a36ef760b6264d18875290ec0 /ruby.html.markdown
parent51c2f7ce28caf1cc654bcafc4063f3012cc2f0c3 (diff)
parent8d1e2e31ef9c62e2833ccb83cde78caef668f044 (diff)
Merge branch 'adambard-master' into r-spanish
Diffstat (limited to 'ruby.html.markdown')
-rw-r--r--ruby.html.markdown46
1 files changed, 40 insertions, 6 deletions
diff --git a/ruby.html.markdown b/ruby.html.markdown
index 998b4bf7..adf5ce81 100644
--- a/ruby.html.markdown
+++ b/ruby.html.markdown
@@ -14,6 +14,7 @@ contributors:
- ["Rahil Momin", "https://github.com/iamrahil"]
- ["Gabriel Halley", "https://github.com/ghalley"]
- ["Persa Zula", "http://persazula.com"]
+ - ["Jake Faris", "https://github.com/farisj"]
---
```ruby
@@ -41,7 +42,11 @@ You shouldn't either
35 / 5 #=> 7
2**5 #=> 32
5 % 3 #=> 2
-5 ^ 6 #=> 3
+
+# Bitwise operators
+3 & 5 #=> 1
+3 | 5 #=> 7
+3 ^ 5 #=> 6
# Arithmetic is just syntactic sugar
# for calling a method on an object
@@ -49,7 +54,7 @@ You shouldn't either
10.* 5 #=> 50
# Special values are objects
-nil # Nothing to see here
+nil # equivalent to null in other languages
true # truth
false # falsehood
@@ -77,6 +82,11 @@ false.class #=> FalseClass
2 <= 2 #=> true
2 >= 2 #=> true
+# Combined comparison operator
+1 <=> 10 #=> -1
+10 <=> 1 #=> 1
+1 <=> 1 #=> 0
+
# Logical operators
true && false #=> false
true || false #=> true
@@ -122,7 +132,7 @@ puts "I'm printing!"
# print to the output without a newline
print "I'm printing!"
-#=> I'm printing! => nill
+#=> I'm printing! => nil
# Variables
x = 25 #=> 25
@@ -220,8 +230,8 @@ new_hash = { defcon: 3, action: true }
new_hash.keys #=> [:defcon, :action]
# Check existence of keys and values in hash
-new_hash.has_key?(:defcon) #=> true
-new_hash.has_value?(3) #=> true
+new_hash.key?(:defcon) #=> true
+new_hash.value?(3) #=> true
# Tip: Both Arrays and Hashes are Enumerable
# They share a lot of useful methods such as each, map, count, and more
@@ -275,7 +285,7 @@ hash.each do |key, value|
puts "#{key} is #{value}"
end
-# If you still need and index you can use "each_with_index" and define an index
+# If you still need an index you can use "each_with_index" and define an index
# variable
array.each_with_index do |element, index|
puts "#{element} is number #{index} in the array"
@@ -401,6 +411,28 @@ def guests(*array)
array.each { |guest| puts guest }
end
+# If a method returns an array, you can use destructuring assignment
+def foods
+ ['pancake', 'sandwich', 'quesadilla']
+end
+breakfast, lunch, dinner = foods
+breakfast #=> 'pancake'
+dinner #=> 'quesadilla'
+
+# By convention, all methods that return booleans end with a question mark
+5.even? # false
+5.odd? # true
+
+# And if a method ends with an exclamation mark, it does something destructive
+# like mutate the receiver. Many methods have a ! version to make a change, and
+# a non-! version to just return a new changed version
+company_name = "Dunder Mifflin"
+company_name.upcase #=> "DUNDER MIFFLIN"
+company_name #=> "Dunder Mifflin"
+company_name.upcase! # we're mutating company_name this time!
+company_name #=> "DUNDER MIFFLIN"
+
+
# Define a class with the class keyword
class Human
@@ -579,7 +611,9 @@ Something.new.qux # => 'qux'
## Additional resources
- [Learn Ruby by Example with Challenges](http://www.learneroo.com/modules/61/nodes/338) - A variant of this reference with in-browser challenges.
+- [An Interactive Tutorial for Ruby](https://rubymonk.com/) - Learn Ruby through a series of interactive tutorials.
- [Official Documentation](http://www.ruby-doc.org/core-2.1.1/)
- [Ruby from other languages](https://www.ruby-lang.org/en/documentation/ruby-from-other-languages/)
- [Programming Ruby](http://www.amazon.com/Programming-Ruby-1-9-2-0-Programmers/dp/1937785491/) - An older [free edition](http://ruby-doc.com/docs/ProgrammingRuby/) is available online.
- [Ruby Style Guide](https://github.com/bbatsov/ruby-style-guide) - A community-driven Ruby coding style guide.
+- [Try Ruby](http://tryruby.org) - Learn the basic of Ruby programming language, interactive in the browser.