我想学 Ruby 系列课程之开篇

为什么学习 Ruby，赞同理由很多，反驳理由也很多。那我就着这里给大家分享下为什么要学习它，到底它有哪些魅力

Transcript

1. 我想学 Ruby 系列 开篇：如何开发者爱上它
2. Teacher.info do realname "⺩王燊" nickname ["三⽕火", "icyleaf"] email “icyleaf.cn@gmail.com” avatar end
3. def what_is_ruby? '⼀一个神奇好玩的编程语⾔言' end
4. def who_made_it! realname "Yukihiro Matsumato" nickname "Matz" country "Janpan" inspired %w[Smatalltalk Perl Lisp] end
5. 著作
6. def why_do_i_need_to_learn_it? ruby_on_rails = 'Ruby语⾔言' + 'Rails框架' read_the_slides! unless u_like_php end
7. def what_makes ruby = :special features = ['真正的⾯面向对象'] features << '脚本语⾔言' features << '开放源代码' # 使⽤用特性 features << '⾯面向开发者设计的语⾔言' features << '丰富的语法糖' features << '实际问题的快速解决⽅方案' # 技术特性 features << "Mixins" features << "消息传递" features << "闭包、函数式编程" features << "庞⼤大的标准库" features << "Rubygems 管理包⼯工具" features << "⾃自动垃圾回收机制" features << "动态类型和鸭⼦子类型" features << "操作重载" features << "⽀支持灵活强⼤大的 DSL 语法定义" end
8. 可是有⼈人告诉我 • Ruby 性能不⾏行，没有 C、C++ ⾼高 • Ruby 需要写 begin … end 渣渣语法体 • 有的⼈人可能还说 Ruby 已死 • ⼩小⽇日本写的，坚决抵制 • …
9. 谁⥈⚂牸
10. 制造快感
12. RubyMotion
13. Opal.rb
14. artoo
15. 变体 基于 Java 实现的 Ruby ⾯面向嵌⼊入式实现的 Ruby ⾯面向 .NET 扩展的 Ruby 使⽤用 Ruby 写 Obj-C
19. 绝对需求量 indeed.com 数据参考
20. 相对增⻓长量 indeed.com 数据参考
21. cio.com 2014年数据参考
24. 编辑器 • IDE: RubyMine / Eclipse • Editor: Sublime text 3 / Atom
25. ⾯面向开发设计的语⾔言
26. ⼀一切万物皆对象
28. if gender.nil? gender = "男" else gender = "⼥女" end
29. gender = if gender.nil? "男" else "⼥女" end
30. gender = (gender.nil?) ? "男" : "⼥女"
31. name = "游客" unless name.empty?
33. 强⼤大的字符集⽀支持 Ruby 1.9+
34. 符号化的优势 同 ⼀一 块 内 存 地 址 不 同 内 存 地 址
35. 要不要这样销魂啊！！
36. 打开你的终端
37. 基本类型
39. Ruby Java Obj-C String String NSString Fixnum Bignum int, long, Integer, Long int, long NSNumber Float Float, Double float NSNumber Array Array NSArray Hash HashMap NSDictionary TrueClass FalseClass Boolean bool NSNumber NilClass null nil Symbol - -
40. 动态语⾔言 + 强类型
42. Array Java Obj-C Type[]
 ArrayList<?>() NSArray NSMutableArray
43. Java int[] intArray = new int[1]; intArray[0] = 1; double[] doubleArray = {1.4, 4.4, 5.1}; ArrayList list = new ArrayList(); list.add("1"); list.add("2");
44. Objective-C NSArray *array1 = [[NSArray alloc] initWithObjects:@3.1, nil]; NSArray *array2 = [NSArray arrayWithObjects:@1, @2.3, @"name", nil]; NSArray *array3 = @[@1, @2.5, @"name"];
45. Ruby array = [1, 2.4, true, [1, 2, 3, 4]] array[0] # => 1 array[2] # => true array[3] # => [1, 2, 3, 4]
46. Hash Java Obj-C HashMap NSDictionary NSMutableDictionary
47. Java HashMap<String , Double> map = new HashMap<String , Double>(); map.put("Apple" , 6.5); map.put("Banana" , 12.0); map.put("Orange" , 8.5);
48. Objective-C NSDictionary *dict1 = [[NSDictionary alloc] initWithObjectsAndKeys: @6.5, @"Apple", @12, @"Banana", @8.5, @"Orange", nil]; NSDictionary *dict2 = @{ @"Apple": @6.5, @"Banana": @12, @"Orange": @8.5 };
49. Ruby hash1 = { :apple => 6.5, :banana => 12, :orange => 8.5 } # Ruby 1.9+ hash2 = { apple: { type1: 6.5, type2: 3 }, banana: 12, orange: 8.5, }
50. 变量
51. 变量的约定 • 定义弱类型（⽆无需预定义） • 不能以数字开头 • 命名约定 • name - 局部变量 • Name - 常量 • @name - 实例变量 • @@name - 类的成员变量 • $name - 全局变量字
52. firstname = 'wang' lastname = 'shen' realname = firstname + " " + lastname same_realname = "#{firstname} #{lastname}" # => wang shen not_realname = '#{firstname} #{lastname}' # => \#{firstname} \#{lastname} # 输出 # Java：System.out.println # Obj-C: printf / NSLog puts realname # => “wang shen" p realname # => “wang shen"
53. 弱语⾔言强类型
54. 流程控制
55. Java Obj-C for(int i; i < {length}; i++){…} for (int i : integers){…} while(true){…} do{…}while(true) for(int i; i < {length}; i++){…} for (int i : integers){…} while(true){…} do{…}while(true) 居然⼀一样？！
56. ⾯面向对象！
57. Ruby [1, 2, 3, 4, 6 - 1].each do |i| puts i end # same above, all the block [1, 2, 3, 4, 6 - 1].each {|i| puts i} {apple:(6.5 * 4), banana:12, orange:8.5}.each do |name, price| puts "#{name} price is #{price.to_s}" end
58. 弱爆了！ JAVA
59. 条件判断
60. Java Ruby Obj-C if (condition){} else if (condition){} else{} if condition … elsif condition … else … end if (condition){} else if (condition){} else{} ⼤大同⼩小异
61. if age.empty? || age.nil? puts "name is empty!" elsif age.length <= 0 puts "age must bigger than 0" else puts “my age is #{age}" end
62. if not ?
63. unless !
64. # same as # if ! age.empty? unless age.empty? puts "age is #{age}" end
65. switch or case ?
66. Java Ruby Obj-C switch (expression) { case n: statements; break; } case expression when n statements when n statements end switch (expression){ case n: statements; break; } Java SE 7+ support String
67. case http_status when 200 puts "OK" when 400..600 puts "System Error" when String puts "What the fxxk ?!" else puts "Unkown Error" end
68. ⽅方法
69. Java Obj-C public String function(String x, int y) {…} public void static function(String x, int y) {…} - (NSString) function (int x, NSString y) {…} + (void) function (int x, NSString y) {…} 依托类 不能独⽴立存在
70. def roles return ['admin', 'user', 'guest'] end
71. def roles ['admin', 'user', 'guest'] end
72. def admin?(name) roles.include?name end puts "icyleaf is admin" if admin?”icyleaf"
73. def add_role(usename, role) user = User.find_by(username: username) user.role.create(name: role)! end add_role("icyleaf", "admin") # same as above add_role "icyleaf", "admin"
74. 类
75. Java Obj-C public class User { String name; int age; public User(String name){…} } # user.h @interface User: NSObject @property NSString *name; @property int age; - (id) initWithName:(NSString *name); @end # user.m @implementation - (id) initWithName:(NSString *name) {…} @end
76. class User def initialize(name) @name = name end def name=(name) @name = name end def name @name end end user = User.new('icyleaf')
77. class User attr_accessor :name def initialize(name) @name = name end end user = User.new("icyleaf") puts user.name user.name = "三⽕火"
78. 模型
79. Java Obj-C package -
80. module Qyer module Mobile class User attr_accessor @name def initialize(name) @name = name end def say_hello puts "hello, mobile guy! #{name}" end end end end user = Qyer::Mobile::User.new(‘icyleaf’) user.say_hello module Qyer module Web class User attr_accessor @name def initialize(name) @name = name end def hello puts "hello, web guy! #{name}" end end end end user = Qyer::Web::User.new(‘master huang') user.say_hello
81. 模型 • 实质上还是 Class • ⽆无法初始化也没有实例
82. 模型不仅仅是命名空间 更多⽤用法后续分解
83. 今天学习 的 怎么样？
85. 课程回顾 • ruby 的简介 • ruby 的应⽤用 • ruby 的市场供需关系 • ruby 的基本类型 • ruby 的变量 • ruby 的流程控制 • ruby 的条件判断 • ruby 的⽅方法、类和模型
87. 答疑时间
88. 反馈调查
89. 今天就到这！ 下课！