Using expression substitution


# you can grab an argument off the command line and add it to the output.

#!/usr/bin/env ruby

puts "Hello, #{ARGV[0]}!"

1.	Interpolation
2.	Interpolating Variables in Double-Quoted Strings
3.	Number value Interpolation
4.	The #{100 * 5} interpolates the result of 100 * 5 (500) into the string at that position
5.	You can interpolate strings too
6.	Constant Interpolation
7.	Call integer.to_s and Interpolation
8.	Use string method in interpolation
9.	Add extra # sign to interpolation
10.	Compare string after interpolation
11.	Put class into interpolation block
12.	Do a calculation in interpolation block
13.	Escape theinterpolation string
14.	Interpolation in Here document

Using expression substitution : Interpolating « Language Basics « Ruby