Introduction
This Ruby mini tutorial should be completed in less than 20 minutes. Assuming you have Ruby installed. (If you have not installed Ruby on your computer yet, download and install Ruby first before you follow this tutorial)
Ruby Obey you!
what just happened? Have we just written the world's shortest program in the form of "Hello World"? Not exactly. The second line is simply an IRB way of telling the result of the last expression being evaluated / executed. If we want to print "Hello World" we need to add a bit:
Your Free Calculator is Here
With IRB we already have enough basic calculator:
Module, Grouping Code By Topic