1：正式的参数不能使实例变量
Ruby1.8
class Foo attr_accessor :bar def test [1,2,3].each {|@bar| } # @bar will be 3 here end end
Ruby1.9
class Foo attr_accessor :bar def test [1,2,3].each {|bar| @bar=bar } # @bar will be 3 here end end
2：覆盖外部局部变量
i =0 [1,2,3].each { |i| } puts i ruby1.8输出3 ruby1.9输出0
3: hash语法 ” , “ 问题
ruby 1.8 {"a","b"} => {"a"=> "b"}
ruby 1.9 {"a" =>＂ｂ＂}
４：字符
默认是 US-ASCIi 码 如果不是的话 用 coding :utf-8
5: String的 ‘to_a’方法未定义
1.8 : string.to_a
1.9 : string.lines.to_a
为了解决兼容性问题keyi :
if str.respond_to?(:lines) then lines = string.lines.to_a else lines = string.to_a end
6: 关键字 then , ; /n case if 可以使用： 代替
1.8:
case 'test' when'test':print 'OK' end
1.9:
case 'test' when'test' then print 'OK' end
7:no such file to load -base64:
require "base64": ruby 1.9 ships without base64. You should use Array#pack, unpack require 'base64' enc = Base64.encode64('Send reinforcements') plain = Base64.decode64(enc) In ruby1.9 you can write: enc = ['Send reinforcements'].pack( 'm' ) plain = enc.unpack( 'm' )[0]
8:'结构体 RStirng没有成员‘ptr’ len
In ruby1.9 for the RString in C extensions was changed because of optimization, you should use the RSTRING_LEN, RSTRING_PTR macros instead of directly accessing the len, ptr members. len = RSTRING(foo)->len ptr = RSTRING(foo)->ptr Should be changed to len = RSTRING_LEN(foo); ptr = RSTRING_PTR(foo);
9:成员改变从Strings转化到Symbols
Object.methods.include?("to_s") The ruby1.9 version is: Object.methods.include?(:to_s) And the following works in ruby1.8 and 1.9: object.respond_to?(:some_method)
10：TypeErro：不能分配nil；要用Hash#delete 代替
n ruby1.8 you can remove an environment variable by setting it to nil. In ruby1.9 use the delete method instead: ENV.delete('MY_ENV_VARIABLE')
