Ruby 为什么非ASCII字符不相等？

我有两个测试用例，其中调用了

data\u valid？

方法。第一个返回

false

，第二个返回

true

，为什么

    55: def data_valid? d
    56:   crc = d[-1]
    57:   data = d[1..-2]
    58:   len = d[0]
 => 59:   binding.pry
    60:   (data ^ len) == crc
    61: end

2.0.0 (#<MicroAeth::Message:0x007fbefc3ceae8>):0 > (data ^ len) == crc
=> false
2.0.0 (#<MicroAeth::Message:0x007fbefc3ceae8>):0 > (data ^ len)
=> "\xB1"
2.0.0 (#<MicroAeth::Message:0x007fbefc3ceae8>):0 > crc
=> "\xB1"
2.0.0 (#<MicroAeth::Message:0x007fbefc3ceae8>):0 > exit
have a good day!
F
From: /Users/rudolph9/Projects/CombustionEmissionsTesting/micro_aeth.rb @ line 59 MicroAeth::Message#data_valid?:

    55: def data_valid? d
    56:   crc = d[-1]
    57:   data = d[1..-2]
    58:   len = d[0]
 => 59:   binding.pry
    60:   (data ^ len) == crc
    61: end

2.0.0 (#<MicroAeth::Message:0x007fbefe83a8c8>):0 > (data ^ len) == crc
=> true
2.0.0 (#<MicroAeth::Message:0x007fbefe83a8c8>):0 > (data ^ len)
=> "+"
2.0.0 (#<MicroAeth::Message:0x007fbefe83a8c8>):0 > crc
=> "+"

我相信这与第一次比较非ASCII字符有关。如何正确设置条件？

您可以使用

String#force_encoding

将字符串强制为指定的编码

2.0.0-p195 :001 > "\xB1".encoding
 => #<Encoding:UTF-8> 
2.0.0-p195 :002 > eight_bit = "\xB1".force_encoding(Encoding::ASCII_8BIT)
 => "\xB1" 
2.0.0-p195 :003 > eight_bit.encoding
 => #<Encoding:ASCII-8BIT> 
2.0.0-p195 :004 > eight_bit == "\xB1"
 => false 
2.0.0-p195 :005 > eight_bit.force_encoding(Encoding::UTF_8) == "\xB1"
 => true
2.0.0-p195 :006 > eight_bit.force_encoding("\xB1".encoding) == "\xB1"
 => true

2.0.0-p195:001>“\xB1”。编码
=> # 
2.0.0-p195:002>八位=“\xB1”。强制编码（编码：：ASCII8bit）
=>“\xB1”
2.0.0-p195:003>八位编码
=> # 
2.0.0-p195:004>八位==“\xB1”
=>错误
2.0.0-p195:005>八位强制编码（编码：：UTF\U 8）==“\xB1”
=>正确
2.0.0-p195:006>八位强制编码（“\xB1”。编码）==“\xB1”
=>正确

---

注意Ruby 2.0.0的默认编码是UTF-8

字符串的编码是什么？请他们检查。@XiongChiamiov

2.0.0（#）：0>crc.encoding=>2.0.0（#）：0>（数据^len）。encoding=>2.0.0（#）：0>（数据^len）。我在转换字符串进行比较时遇到问题：
2.0.0（#）：0>（数据^len（#）：0>crc.encode（data^len）。encoding encoding:：InvaliByteSequenceError:“\xB1”在UTF-8上来自（pry）：13:in
encode'
如何获得公共编码？出于比较目的，我只是将它们转换为整数
（data^len）==crc.byte
。但是，在哪里可以找到有关字符串编码的更详细信息？
2.0.0-p195 :001 > "\xB1".encoding
 => #<Encoding:UTF-8> 
2.0.0-p195 :002 > eight_bit = "\xB1".force_encoding(Encoding::ASCII_8BIT)
 => "\xB1" 
2.0.0-p195 :003 > eight_bit.encoding
 => #<Encoding:ASCII-8BIT> 
2.0.0-p195 :004 > eight_bit == "\xB1"
 => false 
2.0.0-p195 :005 > eight_bit.force_encoding(Encoding::UTF_8) == "\xB1"
 => true
2.0.0-p195 :006 > eight_bit.force_encoding("\xB1".encoding) == "\xB1"
 => true