Ruby: Character to Ascii from a String

Ruby: character to ascii from a string

The c variable already contains the char code!

"string".each_byte do |c|
    puts c
end

yields

115
116
114
105
110
103

ASCII value of character in Ruby

The String#ord method will do the trick:

ruby-1.9.2-p136 > 'x'.ord
 => 120 
ruby-1.9.2-p136 > '0'.ord
 => 48 
ruby-1.9.2-p136 > ' '.ord
 => 32 

Getting an ASCII character code in Ruby using `?` (question mark) fails

Ruby before 1.9 treated characters somewhat inconsistently. ?a and "a"[0] would return an integer representing the character's ASCII value (which was usually not the behavior people were looking for), but in practical use characters would normally be represented by a one-character string. In Ruby 1.9, characters are never mysteriously turned into integers. If you want to get a character's ASCII value, you can use the ord method, like ?a.ord (which returns 97).

Convert string with hex ASCII codes to characters

You can use Array#pack:

["666f6f626172"].pack('H*')
#=> "foobar"

H is the directive for a hex string (high nibble first).

Replacing non standard characters in Ruby

If you want to remove non-ASCII chars, then

strings.map{| s | s.encode('ASCII', 'binary', invalid: :replace, undef: :replace, replace: '')}

What's the opposite of chr() in Ruby?

If String#ord didn't exist in 1.9, it does in 2.0:

"A".ord #=> 65

gsub ASCII code characters from a string in ruby

Update (2018): This code does not work in current Ruby versions. Please refer to other answers.

You can also try

s.gsub(/\xA0|\xC2/, '')

or

s.delete 160.chr+194.chr

How to check if a string contains ASCII code

\x is just a hexadecimal escape sequence. It has nothing to do with encodings on its own. US-ASCII goes from "\x00" to "\x7F" (e.g. "\x41" is the same as "A", "\x30" is "0"). The rest ("\x80" to "\xFF") however are not US-ASCII characters since it's a 7-bit character set.

If you want to check if a string contains only US-ASCII characters, call String#ascii_only?:

p "A\xC3B".ascii_only? # => false
p "\x41BC".ascii_only? # => true

Another example based on your code:

str = "A\xC3B"
unless str.ascii_only?
  str.force_encoding(Encoding::ISO_8859_1).encode!(Encoding::UTF_8)
end
p str.encoding # => #<Encoding:UTF-8>

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