ruby pry

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

Matrix concatenation algorithm implemented by Ruby and ruby matrix concatenation Dynamic Planning solves the problem of matrix concatenation, generates matrix sequences randomly, and outputs results in the form of (A1 (A2A3) (A4A5. Code: #encoding: utf-8=beginauthor: xu jin, 4100213date: Oct 28, 2012MatrixChainto find an optimum order by using MatrixChain algorithmexample output:The given array is:[30, 35,

Simple implementation of the Bubble Sorting Algorithm and Ruby version, and the Bubble Sorting Algorithm ruby Algorithm principle: Compares adjacent elements. If the first is bigger than the second, exchange the two of them.Perform the same operation on each adjacent element, from the first to the last. At this point, the final element should be the largest number.Repeat the preceding steps for all elements

machineInitialization completeStart the environment execution vagrant Halt shutdown environment by executing vagrant up in the appropriate directory when usedOther points of attentionAfter successful initialization, a configuration file named Vagrantfile is generated in the appropriate directory, which can be set for network, memory size, and other content.This article is from the "7692323" blog, please be sure to keep this source http://7702323.blog.51cto.com/7692323/1596334Build a

A few Ruby tips and Ruby tips Sequential call of code blocksCopy codeThe Code is as follows:Def touch_downYield [3, 7]Puts "touchdown! "EndTouch_down do | (first_down, second_down) |Puts "# {first_down} yards on the run"Puts "# {second_down} yards passed"End=> "3 yards on the run"=> "7 yards passed"=> "Touchdown! " It mainly refers to the use of array in block Retrieve elements from arrayCopy codeThe Code i

Example of the use of hundreds of semicolons and literal values in Ruby: ruby percent Use % () (abbreviated as % Q) for a single line string that requires interpolation and embedding double quotation marks ). Multi-line string, preferably heredocs. # bad (no interpolation needed) %( Do not use % q for strings without 'and. Unless many characters need to be escaped, the normal string is more readable.

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:

entities are destroyed Delete_all: All associated entities are deleted directly from the database, unrecoverable nullify: foreign keys are Set to NULL, unrecoverable restrict_with_exception: Throw exception hint Restrict_with_error: Throw error prompt 5, Foreign_key: Define column name for foreign Key 6, inverse_of : Indicates the inverse associated entity 7, Primary_key: Indicates the associated item ID 8, through: Indicates that a many-to-many relationship uses a third-party entity 9, validat

Ruby is a powerful object-oriented scripting language that allows you to quickly and easily object-oriented programming. Sometimes it's a little "fuss" to develop small projects using formal object-oriented languages such as Smalltalk, Eiffel, or C + +. And Ruby just meets the needs of these object-oriented programming. Of course, you can also use Ruby for genera

　　 Brief IntroductionThis article describes how to use the Ruby development tool (RDT) plug-in in Eclipse for Ruby development. This article will benefit the Ruby developers who want to learn how to use the Eclipse infrastructure for Ruby Development, and the Java developers interested in

On the January 15, 2013, Facebook, the famous American social networking platform, launched its own search tool, which injected a new competitive edge into the search field. Earlier, Facebook had hinted at a number of searches and was bullish by

Use C ++ to compile Ruby program extension tutorials. One of Ruby's coolest features is to extend it using the application programming interface (API) defined in C/C ++. Ruby provides the C header file ruby. h, which is accompanied by many features that can be used to create Ruby classes, modules, and more. In addition

Ruby is filled with a series of hidden variables, and we can get some interesting information from these predefined global variables. Global process variables $$ represents the currently running Ruby process. Copy Code code as follows: >> $$ => 17170 We can kill ourselves from the current process. Copy Code code as follows: >> ' kill-9 #{$$} ' [1] 17170 killed IRB $

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

Transferred from: http://www.jb51.net/article/48802.htmRuby is filled with a series of hidden variables, and we can get some interesting information from these pre-defined global variables. Global process variables$$ represents the currently running Ruby process.>> $$= 17170We can kill it ourselves from the current process.>> ' kill-9 #{$$} '[1] 17170 killed IRB$? Represents the state of a recent child process>> ' echo Hello '= "Hello\n">> $?= = #>> $