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48 lines
1.3 KiB
Markdown
48 lines
1.3 KiB
Markdown
# Unpacking Strings Into Binary
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You can find the binary representation of a given string by decoding it. Ruby
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comes equipped with the [`#unpack`](https://apidock.com/ruby/String/unpack)
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method on the `String` class that can do this decoding.
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Though there are a variety of formats to decode a string into, here are some
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example of decoding different characters into binary.
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```ruby
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> "A".unpack("B*")
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=> ["01000001"]
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```
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The `B*` says _unpack_ this into as many *B*inary digits as are needed. The
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UTF-8 encoding, means only a single byte (8-bits) are needed to represent
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`"A"`.
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```ruby
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irb(main):002:0> "Æ".unpack("B*")
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=> ["1100001110000110"]
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irb(main):003:0> "Æ".unpack("B8 B8")
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=> ["11000011", "10000110"]
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```
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`"Æ"` is represented by two bytes. We can unpack each byte seprarately using
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`"B8 B8"`.
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```ruby
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irb(main):004:0> "木".unpack("B*")
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=> ["111001101001110010101000"]
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irb(main):005:0> "木".unpack("B8 B8 B8")
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=> ["11100110", "10011100", "10101000"]
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```
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Similarly, this Japanese character is represented by three bytes of data.
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```ruby
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irb(main):006:0> "👻".unpack("B*")
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=> ["11110000100111111001000110111011"]
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irb(main):007:0> "👻".unpack("B8 B8 B8 B8")
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=> ["11110000", "10011111", "10010001", "10111011"]
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```
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Lastly, emojis generally require four bytes of data.
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[source](https://www.honeybadger.io/blog/the-rubyist-guide-to-unicode-utf8/)
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