How do I remove this backslash in Ruby

How do I remove this backslash?

s = "\""

I have tried s.gsub("\\", "") and that doesn't remove it, it returns 开发者_如何学运维the same string.

there's actually no backslash character in your String. The Backslash in your example simply escapes the following double quote and prevent's that it would terminate the string and thereby resulting in a syntax error (unterminated double quote ).

So what you see when you print that string in IRB is actually not the backslash as is, but the backslash in combination with the following dobule quote as an indication that the double quote is escaped. Kind of hard to grasp when you encounter it the first time. Have a look at http://en.wikibooks.org/wiki/Ruby_Programming/Strings#Escape_sequences

long story short: there is no backslash in your string so you can't remove it :)

gsub takes a regular expression as the first parameter. I believe that if you pass it a string, it will first convert it into a regex. This means you need extra escaping:

s.gsub("\\\\", "")

If you use regex notation, you can stop it from doubling up:

s.gsub(/\\/, "")

This is because you don't have to escape twice: once because double-quoted strings need you to escape the \ character, and once because the regular expression requires you to as well.

that's actually an escape quote sign (do a print s to see it)

I'm not sure if this is a solution to YOUR problem, but seeing that this is one of the first SO questions I looked at when trying to solve my problem and have in fact, solved it, here is what I did to fix my problem.

So I had some CSV.read output with a load of \ (backslashes) and unwanted quotation marks.

arr_of_arrays = CSV.read("path/to/file.csv")

processed_csv = arr_of_arrs.map {|t| eval(t)}

the key here is the eval() method.