eloquent ruby

Installation will not say, the official website has, but today released ruby2.3, so updateEnter the. Rbenv directory, perform a git pull update, but update rbenv, execute rbenv install-l and do not have the latest 2.3.0 release version.Then I looked at the git repository for the Ruby-build plugin, with 2.3 code. Suspect this also to be updated, so.Go to the. Rbenv/plugins/ruby-build directory and execute gi

Ruby parsing JSONRuby Parsing JSON Example: JSON = ' ["A", "B", "C"] ' puts "Unsafe #{unsafe_json (JSON). Inspect}" #输出Unsafe ["A", "B", "C"] Ruby parses JSON to parse the above JSON string into array. Such a method is not safe, for example: JSON = ' puts ' Danger'll Robinson ' puts ' Unsafe #{unsafe_json (JSON). Inspect} " And what should we export? Unfortunately, there is

GitHub advocates a summary of Ruby coding styles, while github advocates ruby code. Source code layout: 1. All source files are UTF-8 encoded2. indent with two spaces3. Use Unix-style line breaks (\ n) and windows (\ r \ n ). You can use git config -- global core. autocrlf true to prevent the generation of windows-style line breaks.4. After ',', ';', add spaces before and after the operator (except for expo

Common Ruby file operation code instances and ruby code instances # Create a 222. rb file and the input character File = file. open ("222.rb"," w + ") file. puts "123 \ nwadwa \ n12124124 \ ndwdw" file. close # output 222. rb content File. open ("222.rb"," r + ") do | file | while line = file. getsputs lineendend # directly use IO to operate the file IO. foreach ("222.rb") do | line | puts line if line = ~

Ruby-implemented file self-deletion code sharing, ruby-implemented code sharing Because the File Deletion mechanism in windows is different from that in unix like, so does not guarantee that the following code can be used in windows. Which of the following kids shoes can help me test it in windows! Copy codeThe Code is as follows:#! /Usr/bin/ruby 5. times do |

1. Auxiliary methods2. StringEnter "IRB" into the ruby command-line development environment, and the controller starts by executing "rails console" on the command line.(1) String connection>>"foo"+"bar"="foobar" (2) Interpolation by special syntax #{}>>first_name="Amy" ="Amy">>" #{first_name} Sun"+"Amy Sun "(3) The difference between a single-quote string and a double-quote string: Single-quote strings they really are literal values, contain only the

When I started my ruby journey, I wrote my study notes for people with other OO language experiences. Let's take a look at the magic ruby. The first sample! First meeting. # ! /Usr/bin/ENV Ruby Class MegagreeterAttr_accessor: names # Create the object Def Initialize (names = " World " )@ Names = NamesEnd # Say hi

Explain the code block object Proc in Ruby, and explain the ruby object proc. Proc object Proc is a block conversion object. There are four methods to create a Proc: Sample Code # Method 1 inc = Proc. new {| x + 1} inc. call (2) #=> 3 # method 2 inc = lambda {| x + 1} inc. call (2) #=> 3 # method 3 inc =-> (x) {x + 1} inc. call (2) #=> 3 # Method 4 inc = proc {| x + 1} inc. call (2) # => 3 In addition to th

Various sorting algorithms implemented by Ruby and Ruby Time Complexity: Average (n ^ 2) Bubble sortCopy codeThe Code is as follows:Def bubble_sort ()(A. size-2). downto (0) do | I |(0.. I). each do | j |A [j], a [j + 1] = a [j + 1], a [j] if a [j]> a [j + 1]EndEndReturnEnd Selection sortCopy codeThe Code is as follows:Def selection_sort ()B = []A. size. times do | I |Min = a. minB A. delete_at (a. index (m

Class methods and class extensions in Ruby object-oriented programming, ruby Object-Oriented Programming Class Method The essence of a class method is a single-piece method that lives in a single-piece class of this class. Three methods are defined: # Method 1 def MyClass. a_class_method; end # method 2 class MyClass def self. anther_class_method; endend # method 3 * class MyClass class The third method in

Ruby-based optimal binary search tree algorithm and ruby-based optimal binary search algorithm The pseudo code in the introduction to algorithms is rewritten, plus the constructor for the solution of the first question in the Introduction Class Exercises.Copy codeThe Code is as follows:# Encoding: UTF-8= BeginAuthor: xu jinDate: Nov 11,201 2Optimal Binary Search TreeTo find by using EditDistance algorithmRe

Comparison of class variables and instance variables in Ruby, ruby class variable instances 1. The class variable name starts with @. A Class variable is shared by all instance objects of the class. The instance variable name starts with @, and each instance object has its own different instance variables; 2. class variables must be initialized before use; otherwise, an error is reported during use. If the

Summary of loop statements in ruby and summary of ruby loop statements While (when ...) Loop 　 　 While Condition Statement 1; Statement 2; statement... End Single Row while LOOP (Statement 1; Statement 2; statement... ) While Condition Until (...) Loop Until condition = while not (condition) For... In Loop 　 　 For variable in obj

String processing in ruby is flexible. "ABC" [0] returns 97 as"ABC" [1] 98"ABC" [2] 99"ABC" [3] Nil"ABC" [-1] 99 forward number"ABC" [-2] 98"ABC" [-3] 97"ABC" [-4] Nil "ABC" * 2 returns "abcabc" supporting Multiplication "ABC" + "def" returns "abcdef" "Abcdef" [] "A" extracts one digit from the position 0"Abcdef" [1, 3] "BCD""Abcdef" [-3, 3] "def""Abcdef" [1 .. 3] "BC" from 1 to 3 Come to a riddleProgram Code highlighting produced by Acti

Arrays in ruby are created by square brackets. The initial values can be placed in square brackets and separated by commas. array elements can be of different types and support addition and multiplication. Ary = [1, 2, "3"]Ary * 2 Returns [1, 2, "3", 1, 2, "3"]Ary + ["Lee", "ho"] returns [1, 2, "3", "Lee", "ho"]Ary [] returns [1, 2] and obtains two elements starting from position 0.Ary [0 .. 2] returns [1, 2, "3"] From position 0 to position 2 Arr

I used to want to use Java for something similar. Today I see Ruby already has ----- Gem install Chardet-y ----- Require 'rubygems'Require 'universaldetector'Require 'net/http'Net: http. version_1_2Net: http. Start ('www .sina.com.cn ') {| HTTP |Data = http. Get ("/"). BodyP universaldetector: chardet (data)}It is a Python version transplant, and there is a confidence parameter. I tested several sites in China and it is very accurate. However,

inheritance of loading modules and classes: Module MdefPuts "' The ' method ' in module M"EndEnd Class CInclude MEnd Class D End obj = d.newObj.reportThe example method is defined in module M, the C class is mixed with module M, Class D is a subclass of Class C, and obj is an instance of Class D, the object of obj can call the method. From an object's perspective, suppose you are an object, someone sends you a message, you have to find a way to respond, and the idea is probably like this:

Here I will not describe the history of the Ruby language. If you're not familiar with Ruby, the official website www.ruby-lang.org is the best place to go. For those who already know Ruby, I am here to give my reasons for falling in love with this (relatively) new language. Ruby is an object-oriented language.What

One of the coolest features of Ruby is to extend it using the Application programming interface (API) defined by C + + +. Ruby provides the C header file Ruby.h, which comes with a number of features that you can use to create Ruby classes, modules, and more. In addition to the header file, Ruby offers several other hi

Ruby is filled with a series of hidden variables. We can get some interesting information from these predefined global variables. Global process variable $ Indicates the currently running ruby process.Copy codeThe Code is as follows: >>$ $=> 17170We can kill ourselves from the current process.Copy codeThe Code is as follows:> 'Kill-9 # {$ $ }'[1] 17170 killed irb$? Indicates the status of the latest sub-pro