Ruby

1. Reference file DifferencesRuby: A file in the same directory, such as/USR/LOCAL/RUBY/FOO.RB and/usr/local/ruby/bar.rb two files. If you are directly in the FOO.RBRequire ' bar 'the BAR.RB error is not found during execution. this is because

Singleton is one design pattern in the software engineering. Ruby has its own special feature to declare Singleton class. I will demonstrate two examples as below:Class logger def initialize @ log = file. open ("log.txt", "A") end @ instance =

Ruby comes with a set of predefined variables $: =Default search path (array of paths)Other Ruby special variables:$! The location where the last error message [email protected] is generated $ _ gets recently read string $. the number of lines

Labels: Install with file OS code I/OInstall RubyYum install Ruby IRB rdoc Install haskallYum install ghc Install Io LanguageTo install the I/O language, install cmake first, but do not use yum for installation. The version of Yum installation is

This series is the answer to the exercises in "seven weeks and seven languages. This book does not stick to syntax details, but compares the programming paradigm between various programming languages (not popular) horizontally. It is a good book

Loop structures are indispensable in programming languages, so loops in Ruby also have their own custom rules. While we focus on the loop structure, we need to know two factors: 1) the condition of the loop; 2) the content of the loop execution Ruby

Conditional judgment exists in programming languages. The conditional judgment in Ruby is similar to that in Java. Of course, there are still some differences. Conditions for condition determination in Ruby: 1) Comparison operations such as =, can

Recently, there is a need to display the number as a fixed number of digits. If the number of digits is insufficient, add it as zero. For example, five digits:Copy codeThe Code is as follows:3-> 00003292-> 0029212422-> 12422Ruby is easy to

New ClassCopy codeThe Code is as follows: ruby script/generate Model :...Ruby script/generate Model Item name: string age: integerRemove ClassCopy codeThe Code is as follows: ruby script/destroy Model New ControllerCopy codeThe Code is as follows:

To understand the Strong Parameters mechanism in Rails 4, first take a look at Parameters in Rails3. When creating or updating an Active Record object in Rails3, there will be a Mass Assignment security issue. Therefore, a whitelist is required in

It took two weeks for Google to deploy the method. Many methods were useless. I finally used the control variable method to modify the configuration file one by one. First,/etc/nginx/vhosts/limlog.sloger.info. conf and config/puma. rb ##

1. Insert sortingCopy codeThe Code is as follows:Seq = [3, 4, 9, 0, 2, 5, 9, 7, 1] 1. upto (seq. length-1) do | I |If seq [I] Tmp = seq [I]J = I-1While (j> = 0 & tmp Seq [j + 1] = seq [j]J = J-1EndSeq [j + 1] = tmpEndEnd Seq. each {| num | puts num}

% Q Used to replace double quotation marks. When you need to put a lot of quotation marks in the string, you can directly use the following method without adding a backslash (\ ") One by one before the quotation marks (\")Copy codeThe Code is as

Ruby Stone scissors cloth game Copy codeThe Code is as follows:# Encoding: UTF-8Arr = ['stone ', 'scissors', 'bo']Win_arr = [['stone ', 'scissors'], ['scissors ', 'cloth'], ['cloth ', 'stone']# Add the random computer value to the result

Tips   Puts Mechanic: AGENT_ALIASES can print out all available user_agent Puts mechanic.instance_methods(false)Output all methods of the Mechanism module Puts mechanic. instance_methods () Outputs all methods of the mechanic module and the

Ruby: complete code for downloading blog articles locally using multiple threads require =page_nums = 8|num|+== |f|== doc.xpath().each do |link|= link[ href.include? $queue.push(link[= File.new(+save_to+,$total_time_begin =threadNums = 10

Introducing Ruby2.0 in advance is a good opportunity to review how to precisely establish method calls using Ruby. Understanding the search method is necessary to grasp the hierarchical classes of Ruby. I have prepared a lot of code examples in this

It has been nearly two years since we used Github in the Global Personals project and following Github Flow. During this period, we submitted thousands of pull requests at a high frequency. Although there were not many suggestions and ideas on how

Profile. rb is the profiler prepared for the Ruby program. It can count and output the running time of each method to locate the performance bottleneck of program execution. This time, we will use it to analyze the running time of the script. The

GitHub address: https://github.com/adamsanderson/qwandry Qwandry can quickly locate the tools we need to find library files and projects. There are many methods for Fast Location in Ruby, And I know three of them: cd `bundle show active_record` Use