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authorAdam <adam@adambard.com>2014-09-06 10:18:55 +0200
committerAdam <adam@adambard.com>2014-09-06 10:18:55 +0200
commit94bdf4c9e58dd206babf4614d238a0c47ba2379d (patch)
tree6664112474e7b8256eebc2c442aa8d37fab57594 /ruby.html.markdown
parent014262f5c62ae1904b5e70135aca8c56540abc78 (diff)
parent4420cd1e6bad8a1c0a4ad6f386a4976f3f7b9ecd (diff)
Merge branch 'master' of github.com:adambard/learnxinyminutes-docs
Diffstat (limited to 'ruby.html.markdown')
-rw-r--r--ruby.html.markdown102
1 files changed, 51 insertions, 51 deletions
diff --git a/ruby.html.markdown b/ruby.html.markdown
index 962853a2..3c67de2e 100644
--- a/ruby.html.markdown
+++ b/ruby.html.markdown
@@ -9,6 +9,7 @@ contributors:
- ["Nick LaMuro", "https://github.com/NickLaMuro"]
- ["Marcos Brizeno", "http://www.about.me/marcosbrizeno"]
- ["Ariel Krakowski", "http://www.learneroo.com"]
+ - ["Dzianis Dashkevich", "https://github.com/dskecse"]
---
@@ -35,7 +36,7 @@ You shouldn't either
8 - 1 #=> 7
10 * 2 #=> 20
35 / 5 #=> 7
-2 ** 5 #=> 32
+2**5 #=> 32
# Arithmetic is just syntactic sugar
# for calling a method on an object
@@ -78,14 +79,17 @@ false.class #=> FalseClass
'I am a string'.class #=> String
"I am a string too".class #=> String
-placeholder = "use string interpolation"
+placeholder = 'use string interpolation'
"I can #{placeholder} when using double quoted strings"
#=> "I can use string interpolation when using double quoted strings"
+# Prefer single quoted strings to double quoted ones where possible
+# Double quoted strings perform additional inner calculations
+
# Combine strings, but not with numbers
-"hello " + "world" #=> "hello world"
-"hello " + 3 #=> TypeError: can't convert Fixnum into String
-"hello " + 3.to_s #=> "hello 3"
+'hello ' + 'world' #=> "hello world"
+'hello ' + 3 #=> TypeError: can't convert Fixnum into String
+'hello ' + 3.to_s #=> "hello 3"
# print to the output
puts "I'm printing!"
@@ -130,7 +134,7 @@ array = [1, 2, 3, 4, 5] #=> [1, 2, 3, 4, 5]
# Arrays can contain different types of items
-[1, "hello", false] #=> [1, "hello", false]
+[1, 'hello', false] #=> [1, "hello", false]
# Arrays can be indexed
# From the front
@@ -157,7 +161,7 @@ array << 6 #=> [1, 2, 3, 4, 5, 6]
# Hashes are Ruby's primary dictionary with keys/value pairs.
# Hashes are denoted with curly braces:
-hash = {'color' => 'green', 'number' => 5}
+hash = { 'color' => 'green', 'number' => 5 }
hash.keys #=> ['color', 'number']
@@ -170,7 +174,7 @@ hash['nothing here'] #=> nil
# Since Ruby 1.9, there's a special syntax when using symbols as keys:
-new_hash = { defcon: 3, action: true}
+new_hash = { defcon: 3, action: true }
new_hash.keys #=> [:defcon, :action]
@@ -180,11 +184,11 @@ new_hash.keys #=> [:defcon, :action]
# Control structures
if true
- "if statement"
+ 'if statement'
elsif false
- "else if, optional"
+ 'else if, optional'
else
- "else, also optional"
+ 'else, also optional'
end
for counter in 1..5
@@ -216,7 +220,7 @@ end
#=> iteration 5
# You can also surround blocks in curly brackets:
-(1..5).each {|counter| puts "iteration #{counter}"}
+(1..5).each { |counter| puts "iteration #{counter}" }
# The contents of data structures can also be iterated using each.
array.each do |element|
@@ -241,32 +245,30 @@ grade = 'B'
case grade
when 'A'
- puts "Way to go kiddo"
+ puts 'Way to go kiddo'
when 'B'
- puts "Better luck next time"
+ puts 'Better luck next time'
when 'C'
- puts "You can do better"
+ puts 'You can do better'
when 'D'
- puts "Scraping through"
+ puts 'Scraping through'
when 'F'
- puts "You failed!"
+ puts 'You failed!'
else
- puts "Alternative grading system, eh?"
+ puts 'Alternative grading system, eh?'
end
-
#=> "Better luck next time"
# cases can also use ranges
grade = 82
case grade
- when 90..100
- puts "Hooray!"
- when 80...90
- puts "OK job"
- else
- puts "You failed!"
+when 90..100
+ puts 'Hooray!'
+when 80...90
+ puts 'OK job'
+else
+ puts 'You failed!'
end
-
#=> "OK job"
@@ -284,23 +286,23 @@ double 3 #=> 6
double double 3 #=> 12
-def sum(x,y)
+def sum(x, y)
x + y
end
# Method arguments are separated by a comma
sum 3, 4 #=> 7
-sum sum(3,4), 5 #=> 12
+sum sum(3, 4), 5 #=> 12
# yield
# All methods have an implicit, optional block parameter
# it can be called with the 'yield' keyword
def surround
- puts "{"
+ puts '{'
yield
- puts "}"
+ puts '}'
end
surround { puts 'hello world' }
@@ -311,25 +313,25 @@ surround { puts 'hello world' }
# You can pass a block to a function
-# "&" marks a reference to a passed block
+# "&" marks a reference to a passed block
def guests(&block)
- block.call "some_argument"
+ block.call 'some_argument'
end
-
+
# You can pass a list of arguments, which will be converted into an array
-# That's what splat operator ("*") is for
+# That's what splat operator ("*") is for
def guests(*array)
- array.each { |guest| puts "#{guest}" }
+ array.each { |guest| puts guest }
end
# Define a class with the class keyword
class Human
# A class variable. It is shared by all instances of this class.
- @@species = "H. sapiens"
+ @@species = 'H. sapiens'
# Basic initializer
- def initialize(name, age=0)
+ def initialize(name, age = 0)
# Assign the argument to the "name" instance variable for the instance
@name = name
# If no age given, we will fall back to the default in the arguments list.
@@ -356,20 +358,19 @@ class Human
# A class method uses self to distinguish from instance methods.
# It can only be called on the class, not an instance.
def self.say(msg)
- puts "#{msg}"
+ puts msg
end
def species
@@species
end
-
end
# Instantiate a class
-jim = Human.new("Jim Halpert")
+jim = Human.new('Jim Halpert')
-dwight = Human.new("Dwight K. Schrute")
+dwight = Human.new('Dwight K. Schrute')
# Let's call a couple of methods
jim.species #=> "H. sapiens"
@@ -380,7 +381,7 @@ dwight.species #=> "H. sapiens"
dwight.name #=> "Dwight K. Schrute"
# Call the class method
-Human.say("Hi") #=> "Hi"
+Human.say('Hi') #=> "Hi"
# Variable's scopes are defined by the way we name them.
# Variables that start with $ have global scope
@@ -399,7 +400,7 @@ defined? @@var #=> "class variable"
Var = "I'm a constant"
defined? Var #=> "constant"
-# Class also is object in ruby. So class can have instance variables.
+# Class is also an object in ruby. So class can have instance variables.
# Class variable is shared among the class and all of its descendants.
# base class
@@ -415,7 +416,7 @@ class Human
end
end
-# derived class
+# derived class
class Worker < Human
end
@@ -451,8 +452,8 @@ module ModuleExample
end
end
-# Including modules binds the methods to the object instance
-# Extending modules binds the methods to the class instance
+# Including modules binds their methods to the class instances
+# Extending modules binds their methods to the class itself
class Person
include ModuleExample
@@ -467,7 +468,7 @@ Person.new.foo # => 'foo'
Book.foo # => 'foo'
Book.new.foo # => NoMethodError: undefined method `foo'
-# Callbacks when including and extending a module are executed
+# Callbacks are executed when including and extending a module
module ConcernExample
def self.included(base)
@@ -500,9 +501,8 @@ 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.
+- [Learn Ruby by Example with Challenges](http://www.learneroo.com/modules/61/nodes/338) - A variant of this reference with in-browser challenges.
- [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 addition](http://ruby-doc.com/docs/ProgrammingRuby/) is available online.
-
-
+- [Programming Ruby](http://www.amazon.com/Programming-Ruby-1-9-2-0-Programmers/dp/1937785491/) - An older [free addition](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.