从字符串中删除首次出现的给定字符

Question

string =

"
[title]

{snippet}

[something else in bracket]

{something else}

more text 

#tags
"

I want to delete first occurrence of [] and {}

s.clean_method or regexp should return string like that

"
title

snippet

[something else in bracket]

{something else}

more text 

#tags
"

Language Ruby 1.9.2

Answer 1

You need String#sub (not gsub):

irb> "[asd]{asd}[asd]{asd}".sub(/\[(.+?)\]/,'\1').sub(/\{(.+?)\}/,'\1')
=> "asdasd[asd]{asd}"

Answer 2

More of the same:

s = "[asd]{asd}[asd]{asd}"
%w({ } [ ]).each{|char| s.sub!(char,'')}
#=> "asdasd[asd]{asd}"

Answer 3

Well, if that's all you want to do, all you need to do is

result = string.sub('{', '').sub('[', '').sub('}', '').sub(']', '')

Of course, that's a terribly inelegant solution, and doesn't consider things like unmatched brackets, etc.

A better solution would probably be:

pattern1 = /\{(.*?)\}/
pattern2 = /\[(.*?)\]/
match1 = pattern1.match(string)
result = string.sub(match1[0], match1[1])
match2 = pattern2.match(result)
result = result.sub(match2[0], match2[1])

This could probably be simplified, but that's what comes off the top of my head :)

BTW, if you want to replace all instances, all you need to do is use gsub instead of sub