Conventions

In this book, you will find a number of text styles that distinguish between different kinds of information. Here are some examples of these styles and an explanation of their meaning.

Code words in text, database table names, folder names, filenames, file extensions, pathnames, dummy URLs, user input, and Twitter handles are shown as follows: "Now if I always want a string to be in lower case letters, I can use the downcase method, like this."

A block of code is set as follows:

10.times do 
  x=10 
end

p x 

When we wish to draw your attention to a particular part of a code block, the relevant lines or items are set in bold:

10.times do 
  x=10 
end

p x 

Any command-line input or output is written as follows:

rvm install 2.3.0 

New terms and important words are shown in bold. Words that you see on the screen, for example, in menus or dialog boxes, appear in the text like this: "When you click on the Download Ruby button, it will take you to the following page."