A method that you define at the top level is stored as a private instance method of the Object class.
Defining private instance methods of Object has some interesting implications.
First, these methods not only can but must be called in bareword style.
Second, private instance methods of Object can be called from anywhere in your code, because Object lies in the method lookup path of every class (except BasicObject, but that’s too special a case to worry about). (查看原文)
A protected method is like a slightly kinder, gentler private method. The rule for pro- tected methods is as follows: you can call a protected method on an object x, as long as the default object (self) is an instance of the same class as x or of an ancestor or descendant class of x’s class.
This rule sounds convoluted. But it’s generally used for a particular reason: you want one instance of a certain class to do something with another instance of its class. (查看原文)
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人民邮电出版社2016版
1 有用 D瓜哥 2015-09-29 16:45:13
深入浅出，并且讲解的很细致，非常棒！👍👍
1 有用 老伐开心 2017-04-26 06:55:48
起点门槛很低, part2有些地方过于API手册了
0 有用 perceptron 2016-10-25 12:06:56
Hands down the best Ruby into book.
0 有用 axl411 2016-05-31 00:47:45
没有太初级，也没有太深的东西，从 Objective-C 来，反正我读得很顺畅。平日用 Ruby 写脚本时遇到 Ruby 写法的问题也会拿出来参考（买的 Manning 网站的 ebook），还是挺好用的。