#!/usr/bin/ruby -w
# This is a single line comment.
puts "Hello, Ruby!"
上述程序执行时，会产生以下结果：
Hello, Ruby!
Ruby的多行注释
可以注释掉多行使用 =begin 和 =end 语法如下:
#!/usr/bin/ruby -w
puts "Hello, Ruby!"
=begin
This is a multiline comment and con spwan as many lines as you
like. But =begin and =end should come in the first line only.
=end
