输出：print、puts、p
注释
#say hello
=begin
this is a long comment
=end
变量
local: time or _time
instance: @time
class: @@time
global $time
数据类型
Numeric
String
Symbol
Boolean
Array
Hash
方法
def plus(x,y)
z = x + y
return z
end
plus(3,4)
def plus x,y
x + y
end
plus 3,4
- 只有overriding没有overloading
block
def hello
yield
end
hello {puts "hello, block"}
[1,2,3,4,5].each{|i| puts i}
[1,2,3,4,5].each_with_index{|i, index| puts i, index}
[1,2,3,4,5].map{|i| i**2 }
[1,2,3,4,5].select{|i| i%2==0 }
[1,2,3,4,5].reject{|i| i%2==0 }
[1,2,3,4,5].inject{|sum, i| sum += i}
lambda 和 Proc
class
class Bird
attr_accessor :name, :sex
attr_reader :age
attr_writer :hometown
def initialize name
@name = name
end
def self.fly
puts "bird can fly"
end
def say
puts "i am #{@name}"
end
end
bird = Bird.new("didi")
bird.sex = "male"
Bird.fly
class LittleBird < Bird
def initialize name
super(name)
end
end
module
- ruby 没有interface，但是有 module 与 mixin 机制。
module Eat
def eat
p "i can eat"
end
end
module Sleep
def sleep
p "i can sleep"
end
end
class Pig
include Eat
include Sleep
end
Pig.new.eat
Pig.new.sleep
module Math
PI = 3.14
end
Math::PI
code
r1.rb
