Tutorial on interrupt and return in Ruby programming and tutorial on ruby programming usage
The use of the return, break, and next keywords involves the issue of jumping out of the scope. Their difference lies in the different scopes of different keywords jumping out, because there are code blocks, you need to pay special attention to them.ReturnCommon Methods
Generally, the return statement is the same as
Example parsing for Hook methods in Ruby and ruby hook instance Parsing
By using the Hook method, we can intervene in the life cycle of Ruby classes or modules, greatly improving programming flexibility.The following hook methods related to lifecycle are available:
Classes and modules
Class # inherited
Module # include
Module # prepended
Module # extend_
Let's get back to our jukebox for a moment (remember the jukebox ?). At some point
We'll be working on the code that handles the user interface-the buttons that people
Press to select songs and control the jukebox. We'll need to associate actions
Those buttons: press START and the music starts. It turns out that Ruby's blocks are
A convenient way to do this. Let's start by assuming that the people who made
Hardware implemented a Ruby extension that gi
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
Introduction to file operations in Ruby and file operations in ruby
Ruby provides a complete set of I/O-related kernel modules. All I/O methods come from IO classes.
Class IO provides all the basic methods, such as read, write, gets, puts, readline, getc, and printf.
This chapter covers all basic I/O functions available in Ru
Ruby image installation, ruby Image
Because of the domestic network, the intermittent connection of resource files stored on Amazon S3 by rubygems.org fails. So you willgem install rackOrbundle installHalf a day without response.gem install rails -VTo view the execution process.This is a complete rubygems.org image. You can use this image to replace the official version. The synchronization frequency is cu
The example explains how Ruby uses the decorator mode in the design mode, and the ruby design mode.
OverviewIf you are engaged in object-oriented development, adding behavior to a class or object and using inheritance mechanisms, this is a basic feature of all object-oriented languages. If an existing class lacks some methods, or you need to add more functions (CHARM) to the method ), you may just inherit t
Solve ruby Installation Problems: redis requires Ruby version amp, rubyredis
I. Problem Description
Today, we set up a redis cluster and encountered a problem when installing ruby and redis interface programs: redis requires Ruby version> = 2.2.2., as shown below:
[root@localhost ~]# gem install redis-4.0.0.gem ERROR
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
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
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