First Ruby Program: Ruby Study Notes. Let's open up our plain- text editor. As far as possible, ensure that your editor's Tab is set to 2 spaces. We are now ready to write our first Ruby program. Code layout is pretty much up to you; indentation is not significant (but using two- character indentation will make you friends in the community if you plan on distributing your code). Create a folder named, say. We shall store all our programs in this folder. Our first program will display the string 'Hello' on the command window and the name of the program will be say p. By convention, Ruby source files have the . In Microsoft Windows, Ruby source files sometimes end with . Getting Started with Ruby. We will also look at how you can turn your Ruby program into a web application and see it running in a browser. The Ruby language has a very simple control structure that is easy to read and follow. Ruby If, Else If Command Syntax. Classic Hello world example. Yielding the flow of program control to a block that was provided at calling time. The Ruby coding convention states that file/directory name is lower case of class/module name with . For example, Foo class has name foo. Type the following in your editor. Hello'. and then click File/Save As.. Give the name p. 00. A look at several of the existing Ruby gems for creating command line interfaces (pros and cons, ease of use, etc.), along with example code for each. Input & output in Ruby. In this part of the Ruby tutorial, we will talk about input & output operations in Ruby. Input is any data that is read by the program, either from a keyboard, file or other programs. Contrary if you want system first to search other folders and at the end to. To run your program, open a command window and type ruby p. Hello. c: \rubyprograms>. You should see the output as shown above. Note: Ruby is a scripting language. There is no special main method in Ruby from which execution begins. The Ruby interpreter is given a script of statements to execute, and it begins executing at the first line and continues to the last line. Parentheses are usually optional with a method call. These calls are all valid: foobarfoobar()foobar(a, b, c)foobar a, b, cb. In Ruby, everything from an integer to a string is considered to be an object (more on this later). And each object has built in 'methods' (Ruby term for functions) which can be used to do various useful things. To use a method, you need to put a dot after the object, and then append the method name. Some methods such as puts and gets are available everywhere and don't need to be associated with a specific object. Technically speaking, these methods are provided by Ruby's Kernel module (more on this later) and they are included in all Ruby objects (the Kernel module is included by class (more on this later) Object, so its methods are available in every Ruby object). When you run a Ruby application, an object called main of class Object is automatically created. This object provides access to the Kernel methods. Observe: Java and C programmers - no need to write a main method/function. String literals are sequences of characters between single or double quotation marks. Ruby is an interpreted language, so you don't have to recompile to execute the program written in Ruby. The Ruby coding convention states that file/directory name is lower case of class/module name with . For example, Foo class has name foo. Note: The Ruby Logo is Copyright (c) 2. Yukihiro Matsumoto. I have made extensive references to information, related to Ruby, available in the public domain (wikis and the blogs, articles of various Ruby Gurus), my acknowledgment and thanks to all of them. Much of the material on rubylearning. Programming Ruby book, available from The Pragmatic Bookshelf.
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