How to print a string with a backward slash in Ruby
-
30-05-2021 - |
Frage
I have a string str = "xyz\123"
and I want to print it as is.
The IRB is giving me an unexpected output. Please find the same below:-
1.9.2p290 :003 > str = "xyz\123"
=> "xyzS"
1.9.2p290 :004 >
Any ideas on how can I get IRB to print the original string i.e. "xyz\123".
Thank you..
UPDATE :
I tried escaping it , but it doesn't seem to be that simple for some reason. Please find below my trials with the same:
1.9.2p290 :004 > str = "xyz'\'123"
=> "xyz''123"
1.9.2p290 :005 > str = "xyz'\\'123"
=> "xyz'\\'123"
1.9.2p290 :006 > str = "xyz'\\\'123"
=> "xyz'\\'123"
1.9.2p290 :007 >
Lösung
UPDATED answer:
escape token '\' is always working in plain ruby code, but not always working in "ruby console". so I suggest you write a unit test:
# escape_token_test.rb
require 'test/unit'
class EscapeTokenTest < Test::Unit::TestCase
def test_how_to_escape
hi = "hi\\backslash"
puts hi
end
end
and you will get result as:
hi\backslash
and see @pst's comment.
Andere Tipps
The backslash character is an escape character. You may have seen "\n" be used to display a new line, and that is why. "\123" evaulates the ASCII code for 83, which is "S". To print a backslash use 2 backslashes. So you could use str = "xyz\\123"
.
How to print a backslash?
Use 2 backslashes, e.g. "xyz\\123"
Why does "xyz\123"
evaluate to "xyzS"
?
In a double-quoted string, \nnn
is an octal escape.
Thomas, D. (2009) Programming Ruby, p.329
So, octal 123
= (64 * 1) + (8 * 2) + 3
= decimal 83
= ASCII S
It's simple ... try dump function:
mystring = %Q{"Double Quotes"}
p mystring.dump
=> "\"\\\"Double Quotes\\\"\""
p mystring
=>"\"Double Quotes\""