Ruby，一种简单快捷的面向对象（面向对象程序设计）脚本语言，键入irb将进入Ruby的互动环境。
:foobar.object_id # 回传Ruby内部的内存配置编号
5.times # 五次
nil.nil? # 未设定值、未定义
puts a.inspect # 输出 [1, "cat", nil]
colors = ["red", "blue"]
colors.push("black")
colors << "white"
puts colors.join(", ") # red, blue, black, white
colors.popputs
colors.last #black
languages.each do |lang|
puts 'I love ' + lang + '!'
end
config = { foo: 123, bar: 456 } # 等同于 { :foo => 123, :bar => 456 }
config.each do |key, value|
puts "#{key} is #{value}"
end
puts "greater than ten" if total > 10
if total > 100000
puts "large account"
end
expression ? true_expresion : false_expression
case name
when "John"
puts "Howdy John!"
when "Ryan"
puts "Whatz up Ryan!"
else
puts "Hi #{name}!"
end只有false和nil是假，其他都为真。
