summaryrefslogtreecommitdiffhomepage
path: root/ruby.html.markdown
diff options
context:
space:
mode:
Diffstat (limited to 'ruby.html.markdown')
-rw-r--r--ruby.html.markdown62
1 files changed, 57 insertions, 5 deletions
diff --git a/ruby.html.markdown b/ruby.html.markdown
index 7bd28d86..3eed2d3c 100644
--- a/ruby.html.markdown
+++ b/ruby.html.markdown
@@ -12,7 +12,9 @@ contributors:
- ["Dzianis Dashkevich", "https://github.com/dskecse"]
- ["Levi Bostian", "https://github.com/levibostian"]
- ["Rahil Momin", "https://github.com/iamrahil"]
-
+ - ["Gabriel Halley", "https://github.com/ghalley"]
+ - ["Persa Zula", "http://persazula.com"]
+ - ["Jake Faris", "https://github.com/farisj"]
---
```ruby
@@ -39,6 +41,12 @@ You shouldn't either
10 * 2 #=> 20
35 / 5 #=> 7
2**5 #=> 32
+5 % 3 #=> 2
+
+# Bitwise operators
+3 & 5 #=> 1
+3 | 5 #=> 7
+3 ^ 5 #=> 6
# Arithmetic is just syntactic sugar
# for calling a method on an object
@@ -46,7 +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
@@ -74,6 +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
@@ -106,8 +119,20 @@ placeholder = 'use string interpolation'
'hello ' + 3 #=> TypeError: can't convert Fixnum into String
'hello ' + 3.to_s #=> "hello 3"
-# print to the output
+# Combine strings and operators
+'hello ' * 3 #=> "hello hello hello "
+
+# Append to string
+'hello' << ' world' #=> "hello world"
+
+# print to the output with a newline at the end
puts "I'm printing!"
+#=> I'm printing!
+#=> nil
+
+# print to the output without a newline
+print "I'm printing!"
+#=> I'm printing! => nil
# Variables
x = 25 #=> 25
@@ -154,6 +179,7 @@ array = [1, 2, 3, 4, 5] #=> [1, 2, 3, 4, 5]
# Arrays can be indexed
# From the front
array[0] #=> 1
+array.first #=> 1
array[12] #=> nil
# Like arithmetic, [var] access
@@ -164,10 +190,15 @@ array.[] 12 #=> nil
# From the end
array[-1] #=> 5
+array.last #=> 5
# With a start index and length
array[2, 3] #=> [3, 4, 5]
+# Reverse an Array
+a=[1,2,3]
+a.reverse! #=> [3,2,1]
+
# Or with a range
array[1..3] #=> [2, 3, 4]
@@ -199,8 +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
@@ -254,6 +285,12 @@ 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
+# variable
+array.each_with_index do |element, index|
+ puts "#{element} is number #{index} in the array"
+end
+
counter = 1
while counter <= 5 do
puts "iteration #{counter}"
@@ -265,6 +302,19 @@ end
#=> iteration 4
#=> iteration 5
+# There are a bunch of other helpful looping functions in Ruby,
+# for example "map", "reduce", "inject", the list goes on. Map,
+# for instance, takes the array it's looping over, does something
+# to it as defined in your block, and returns an entirely new array.
+array = [1,2,3,4,5]
+doubled = array.map do |element|
+ element * 2
+end
+puts doubled
+#=> [2,4,6,8,10]
+puts array
+#=> [1,2,3,4,5]
+
grade = 'B'
case grade
@@ -539,7 +589,9 @@ 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.