Ruby: character to ascii from a string

Question

this wiki page gave a general idea of how to convert a single char to ascii http://en.wikibooks.org/wiki/Ruby_Programming/ASCII

But say if I have a string and I wanted to get each character's ascii from it, what do i need to do?

"string".each_byte do |c|
      $char = c.chr
      $ascii = ?char
      puts $ascii
end

It doesn't work because it's not happy with the line $ascii = ?char

syntax error, unexpected '?'
      $ascii = ?char
                ^

score 57 · Accepted Answer · answered Sep 27 '08 at 15:37

57

The c variable already contains the char code!

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

yields

answered Sep 27 '08 at 15:37

Konrad Rudolph

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score 22 · Answer 2 · edited Mar 19 '12 at 18:41

22

puts "string".split('').map(&:ord).to_s

edited Mar 19 '12 at 18:41

Rafał Rawicki

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answered Mar 19 '12 at 16:37

alexsuslin

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10

even nicer than `split('')` is calling `chars` – phoet Sep 15 '13 at 11:51

score 12 · Answer 3 · answered Dec 15 '13 at 19:59

12

use "x".ord for a single character or "xyz".sum for a whole string.

answered Dec 15 '13 at 19:59

Sh.K

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score 12 · Answer 4 · edited Apr 03 '22 at 18:38

12

Ruby String provides the codepoints method after 1.9.1.

str = 'hello world'
str.codepoints
=> [104, 101, 108, 108, 111, 32, 119, 111, 114, 108, 100] 

str = "你好世界"
str.codepoints
=> [20320, 22909, 19990, 30028]

edited Apr 03 '22 at 18:38

Community

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answered Jul 23 '15 at 14:55

LastZactionHero

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do you actually need the `.to_a` after codepoints? Seems like `codepoints` already returns an array `"abcde".codepoints.class #=> Array` – dcts Apr 13 '19 at 22:27

score 8 · Answer 5 · edited May 23 '17 at 12:34

8

please refer to this post for the changes in ruby1.9 Getting an ASCII character code in Ruby using `?` (question mark) fails

edited May 23 '17 at 12:34

Community

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answered Mar 03 '10 at 09:50

nikkypx · Answer 6 · 2015-11-13T19:56:46.127

8

You could also just call to_a after each_byte or even better String#bytes

=> 'hello world'.each_byte.to_a
=> [104, 101, 108, 108, 111, 32, 119, 111, 114, 108, 100]

=> 'hello world'.bytes
=> [104, 101, 108, 108, 111, 32, 119, 111, 114, 108, 100]

edited Nov 13 '15 at 19:56

answered Nov 13 '15 at 19:31

nikkypx

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score 4 · Answer 7 · answered Oct 13 '09 at 00:53

4

"a"[0]

or

?a

Both would return their ASCII equivalent.

answered Oct 13 '09 at 00:53

Mark

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Did this change in Ruby 1.9 ? – Gishu Nov 12 '09 at 10:12
1

Yea, in Ruby 1.8 it return the characters ascii value, but it ruby the character at the index in ruby 1.9... – David Jun 27 '10 at 15:22
10

`"a"[0].ord` should return the ascii code. Note that it's actually a unicode code. – albert Oct 01 '11 at 07:08

Ruby: character to ascii from a string

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