Question

How to check whether a string contains special character in ruby. If I get regular expression also it is fine.

Please let me know

Answer 1

special = "?<>',?[]}{=-)(*&^%$#`~{}"
regex = /[#{special.gsub(/./){|char| "\\#{char}"}}]/

You can then use the regex to test if a string contains the special character:

if some_string =~ regex

This looks a bit complicated: what’s going on in this bit

special.gsub(/./){|char| "\\#{char}"}

is to turn this

"?<>',?[]}{=-)(*&^%$#`~{}"

into this:

"\\?\\<\\>\\'\\,\\?\\[\\]\\}\\{\\=\\-\\)\\(\\*\\&\\^\\%\\$\\#\\`\\~\\{\\}"

Which is every character in special, escaped with a \ (which itself is escaped in the string, ie \\ not \). This is then used to build a regex like this:

/[<every character in special, escaped>]/