elixir ruby

1. Debug comment Print output debugRuby is an interpreted language, a script, and on Linux, scripts cannot be executed in three ways:1. Run the script with the interpreterInterpreter script FileThat is:Ruby script File2. Run the script directlyIn the script file, use the#! Script InterpreterDefine the script interpreter path, then grant the script execute permission, then run directly./script FileCan.3. Run the script inside the interpreter[Email protected]:/home/ywt/ror_tests/ruby_tests# irb

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.

Methods (functions) in Ruby, ruby Functions 1. The method name and variable name naming rules in Ruby are the same (Start with a lower-case letter, and separate words with "_",), but you can add it behind the method name! (Major method) or? (Boolean return value ). 2. Use () for method parameters (),All parameters are local variables. You can set the default valu

Ruby implements batch code sharing by adding prefixes to files, and ruby Prefix code sharing From the perspective of the designer, we get a large number of images, and the results are all file names such as 1.png and 2.png. We also need to convert these files into readable file names and do not want to modify them one by one, so we wrote a simple script, you can add prefixes to multiple files in batches. Yo

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

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

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