ruby splat

I have recently considered a lot of metaprogramming (metaprogramming) issues and would like to see more examples and explanations of this technology. For better or worse, Metaprogramming has entered the Ruby community and is a standard way to accomplish various tasks and simplify code. Since I can't find this kind of resources, I'm going to start writing some general Ruby technology articles. These may be u

Example of writing code for exception handling in Ruby, and ruby Exception Handling A single exception uses the fail keyword only when an exception is caught and thrown repeatedly (because you do not fail here, but are accurate and intentionally throw an exception ). begin fail 'Oops' rescue => error raise if error.message != 'Oops' end Do not specify an accurate RuntimeError for fail/raise. # bad

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

A Date and Time Processing tutorial in Ruby and a date Processing tutorial in ruby The Time class is used in Ruby to represent the date and Time. It is based on the system date and time provided by the operating system. This type may not represent the date before or after January 1. This tutorial will familiarize you with all important concepts of date and time.C

Analysis of Ruby source code layout and programming style, analysis of ruby source code Layout Use the UTF-8 as the source file encoding. Each indentation level uses two spaces (also known as soft tabs). Do not use hard tabs # bad - four spaces def some_method do_something end # good def some_method do_something end Use Unix-style line breaks. (* Users of BSD, Solaris, Linux, and OSX are covered

Ruby learning plan-(0) preface, ruby Preface Preface Currently, C, C ++, Java, Object-C, and Swift programming languages have been used. The most familiar language is oc. After all, it depends on him for dinner. It is only a beginner's path for other languages. Because he has been engaged in iPhone app development, recently, I wanted to develop a project by myself, but there was no backend, so I was so

Global variable $ XX Object variable @ xx Local variable [A-Z] xx Constant [A-Z] xx Two pseudo variables self and nil:Self is actually a global variable pointing to the current object. The value of this variable is controlled by the interpreter and can only be read and cannot be modified.Nil is also a global variable controlled by the interpreter and cannot be assigned a value. 1. Global variable $ XXGlobal variables should be used with caution because their scope is script-level and can

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