1. $a全局变量 @a 实例变量 @@a 类变量 类变量，模块名称和常量以大写字母开头
2. string数组的构建 arr=%w{hello work 123}
3. 双引号字符串会进行转义和内插，单引号就直接保留原值。
greeting="hello"
@a=4, $num=5
'#{greeting}, Jim' -->#{greeting}, Jim
"#{greeting}, Jim, #@a @$num" --> hello, Jim, 4 5
4. "0kjshellohe" =~ /he/ -->4
5. block
def fun
yield(3,4)
end
fun {|n1, n2| n1+n2;} -->7
6. 实例方法和类方法
class Animal
private_class_method :new
public :speak
def initialize name
@name=name
end
def speak
puts self.mie+"#@name is speaking..."
end
private
def mie
"mie"
end
=begin
类方法
=end
def Animal.sleep
puts "Animal is sleeping..."
end
end
7. 数组
a=[] <=>a=Array.new
a[3,-1], a[1...3]