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The example explains the Hook method in Ruby and adds a hook to the method call. The example explains ruby. The Hook method is similar to the event-driven device. You can execute a specific callback function after a specific event occurs. This callback function is the hook method (more vividly described: The Hook method can be like a hook, hook up a specific event .), In Rails, The before \ after function i

Detailed description of the code block and parameter transfer in Ruby, detailed description of ruby code transfer 1. Block DeclarationAfter the function is called, the block declaration is enclosed by {...}, Or do. end encapsulation. {} Is generally used in single-line statements, and do... end is used in multi-line statements. (1 .. 4). each {| v | print "# {v}"} # output 1 2 3 4 Blocks can contain paramet

The example parses the value types and constants in Ruby AND the ruby numerical constants. Number)Integer)There are two types of integer types. If the value is within 31 characters (four bytes), it is a Fixnum instance. If the value is exceeded, it is a Bignum instance.The integer ranges from-230 to 230-1 or-262 to 262-1. Integers in this range are Fixnum-like objects, and integers out of this range are sto

Ruby class inheritance, abstract classes, class expansion, proxy class instances, ruby instances Summarize the class extensions encountered in the work: 1. class inheritance: When multiple classes share many methods, you can extract the public methods and inherit the required classes. Example: Copy codeThe Code is as follows:Class A DefP "it was"EndEnd Class B End Class C End B. new. a # => "it was"C. new.

Statistics on the number of file lines, number of words, and number of characters in Ruby, and number of ruby lines In Ruby, we define a wc method to count the number of lines, words, and characters in the file. The ruby code program is as follows:Copy codeThe Code is as follows:Def wc (filename)Nline = nword = nchar

Brief explanation of the scope of Ruby Object-Oriented Programming and ruby Object-Oriented Programming Scope Ruby does not have nested scopes (internal scopes, which can be viewed as external scopes). Their scopes are completely separated. Once a new scope is entered, the original binding will be replaced with a new binding group. The program will close the prev

Ruby Web Real-Time Message backend server push technology --- GoEasy, ruby --- goeasy More and more projects require real-time message pushing and receiving. How can we use Ruby to achieve the most convenient? We recommend that you use GoEasy, a third-party PUSH Service Platform. You can use its APIs to easily push messages in real time! Browser compatibility: Go

Ruby concise learning notes (2): class inheritance, attributes, class variables, and ruby learning notes 1. How to declare a subclassCopy codeThe Code is as follows:Class Treasure In this way, the property names and descriptions of Thing classes are inherited by Treasure. 2. What are the parameters used to pass in the initialize method of the parent class in the following three methods?Copy codeThe Code is

Ruby Plus is a site offering free Ruby and rails related screencasts recorded by Bala paranj, much in the same vein as Ryan Bates 'railscasts. the screencasts are generally similar in length and overall format to those from railscasts. so far there are 29 episodes you can download. The first twelve screencasts in the archive (for which you have to register to download, alas) were exclusively

Ruby implements the insertion Sorting Algorithm and the advanced two-way insertion sorting code example, ruby two-way BasicInsert a record to a sorted table to obtain an ordered table with one added record. In addition, the most critical point is that it moves all records larger than the current element to leave the insert position "self. After n-1 troughs are inserted, the record is an ordered sequence. De

Read Ruby metaprogramming and ruby metaprogrammingUsing many spells and Ruby's programming skills to implement many clever programming:Array parametersSurrounding aliasWhiteboardClass ExtensionClass ExtensionClass instance variablesClass macrosClean RoomCode ProcessorContext probesDelayed executionDynamic DistributionDynamic MethodDynamic proxyFlat ScopeGhost MethodHook methodKernel MethodInertia instance v

Import Java.io.BufferedReader;Import Java.io.InputStreamReader;public class Cmd_ruby {private static string Execmd (String commandstr) {BufferedReader br = null;try {Process p = runtime.getruntime (). exec (COMMANDSTR);br = new BufferedReader (New InputStreamReader (P.getinputstream ()));String line = null;StringBuilder sb = new StringBuilder ();while (line = Br.readline ()) = null) {Sb.append (line + "\ n");}System.out.println (Sb.tostring ());return sb.tostring ();} catch (Exception e) {E.prin

1. Invocation of the method2. Custom method3. Custom methods with default values4. Custom method with return valueA method, or a function, actually contains a piece of code to perform a particular process.def Add (a=3,b=2) return A +bend' /study/ruby/intro_rails/maizi/381-4026/08function.rb '= = TRUEIRB (main):003:0> Add= 5irb (main):004:0> add 4=> 6IRB (main):005:0> Add 4,5=> 9IRB (main):"Ruby on Rails

Ruby-implemented image filter algorithm code, ruby-implemented Filter Algorithm Source image I. grayscale Algorithms The color values of each pixel in a color photo are composed of three values: Red, green, and blue. The values of red, green, and blue are different. Therefore, the color values of pixels can also contain many color values, this is the principle of a color image, while a gray-scale image has

Ruby metaprogramming and ruby Programming An object model Kernel Module Kernel. private_instance_methods.grep (/^ pr /) Private method 1. If a method receiver is not yourself, you must specify a receiver. 2. A private method can only specify one implicit receiver (a private method that can be called as a superclass) The Class itself is the object of the Class. The class name is a constant. Class

Ruby Study Notes 1: Ruby Study Notes Notes: Ruby returns the last value in the method by default.To return multiple values, you can use an array.You can return a value by forcibly declaring return.The basic output method is to use puts (output line) and print (print directly ).The Basic Input Method is gets (read a row that contains '\ n' at the end of the row, w

Multiple ruby traversal folder code instances collected, ruby instances 1. traverse all files in the folder and output file names Copy codeThe Code is as follows:Def traverse_dir (file_path)If File. directory? File_pathDir. foreach (file_path) do | file |If file! = "." And file! = ".."Traverse_dir (file_path + "/" + file)EndEndElsePuts "File :#{ File. basename (file_path)}, Size: # {File. size (file_path )}

Ruby implements the active mail push trigger program, and ruby implements mail triggering After receiving the email, the mail server pushes the notification program. Is there any way to achieve this? 1. Client polling2. The server actively pushes data. First, familiarize yourself with the protocol for sending and receiving emails:Net: SMTP (send mail)Net: POP3 (receive mail)Net: IMAP (receive mail) There ar

A summary of some common file operations in Ruby and a summary of ruby operations A lot of Ruby beginners need to learn. Now we are trying to use Ruby to write a script. Many file-related operations are used, which are sorted in stages here. This facilitates subsequent searches. Whether the file or directory exists

Collections writing guide in Ruby and Ruby collections writing guide Preference array and the literal representation of Hash (unless you need to pass parameters to their constructor ). # bad arr = Array.new hash = Hash.new # good arr = [] hash = {} When you need an array with elements of words (no spaces or special characters), you always use % w to define a string array. Apply this rule to only two