Dogs have many shared characteristics, like the abilities to wag their tails and drink water from a bowl, but they also have information about them that is variable, like their breed or their name. Similarly, when designing an application, your users…

https://github.com/unixc3t/mydoc/blob/master/blog/caiv.md…

Avoid Properties in Categories Objective-C分类中是不允许增加成员变量的(Instance variables may not be placed in categories),我们可以通过运行时函数objc_setAssociatedObject 和 objc_getAssociatedObject 来让分类支持保存和获取一些数据,从而支持属性. //EOCPerson+FriendShip.h @interface EOCPerson (FriendS…

是一个概念 Stored Properties and Instance Variables If you have experience with Objective-C, you may know that it provides two ways to store values and references as part of a class instance. In addition to properties, you can use instance variables as a…

When calling an instance method like withdraw_securely, the syntax generally looks something like this: object.method_being_called(arguments) One would therefore think it’s safe to assume that an instance method is always preceded by a ., which is in…

Install Ruby(安装) For windows you can download Ruby from http://rubyforge.org/frs/?group_id=167 for Linux tryhttp://www.rpmfind.net. Our first program(从此开始) Enter the following into the file, "test.rb". puts "Howdy!" At the C: prompt en…

ruby对象是严格封装的:只能通过定义的方法访问其内部状态.方法使用的成员变量在对象外部不能直接访问,不过可以通过getter.setter等访问器方法(accessor),使他们看起来好像是直接访问的. 与对象状态的封装性相反,ruby中的类非常开放.每个ruby程序都可以为现有类添加方法,而且也可以为单个对象添加“单键方法(singleton method)”. 创建类 Classes are created in Ruby with the class keyword:class Poin…

赋值: ruby支持并行赋值,即允许在赋值表达式中出现多余一个值和多于一个的变量: x,y=1,2a,b=b,ax,y,z=[1,2,3] (python同样可以正常上面的语句). Methods in Ruby are allowed to return more than one value, and parallel assignmentis helpful in conjunction with such methods. For example:# Define a method to…

1.block 代码块 do...end 或 {} 构成一个代码块,就像常见的 .each后面跟的代码块. my_nums = [1,2,3] my_double_nums = my_nums.collect {|num| num*2} puts "#{my_double_nums}" #=> [2,4,6] collect能作用在Array的每个元素上,也支持collect! 操作,即改变数组本身.map! 和 collect! 作用相同 yield关键字 yield能够在方法…

前情提要 在第一天里,我很激昂地用Ruby的类别.物件.方法,写了宣言! class TingIsIronman def initialize @message =“I'm going to write 30 IT articles in 30 days!” end def method puts @message.gsub(“write”,“create”) end end object = TingIsIronman.new object.method #=> I'm going to cr…