Ruby string strip defined characters

In Python, we can use the [`.strip()`][1] method of a string to remove leading or trailing occurrences of chosen characters:

<pre><code>>>> <b>print " (Removes (only) leading & trailing brackets & ws ) ".strip(" ()")</b>
'Removes (only) leading & trailing brackets & ws'</code></pre>

How do we do this in Ruby? Ruby's [`strip`][2] method takes no arguments and strips only whitespace.

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Ruby now includes full support for stripping with

lstrip: Strips only leading part of string
rstrip: Strips only ending part of string
strip: Strips both leading and ending of string

You can use:
str.chomp('.')
that works for trailing characters and you can reverse the string for leading characters:
str.reverse.chomp('.').reverse

To do both at once you can:
str.chomp('.').reverse.chomp('.').reverse

Note: chomp removes only one occurrence by default

There is no such method in ruby, but you can easily define it like:

def my_strip(string, chars)
chars = Regexp.escape(chars)
string.gsub(/\A[#{chars}]+|[#{chars}]+\z/, "")
end

my_strip " [la[]la] ", " []"
#=> "la[]la"

Try the `String#delete` method: (avaiable in 1.9.3, not sure about other versions)

Ex:

1.9.3-p484 :003 > "hehhhy".delete("h")
=> "ey"

There is no such method in ruby, but you can easily define it like:

class String
alias strip_ws strip
def strip chr=nil
return self.strip_ws if chr.nil?
self.gsub /^[#{Regexp.escape(chr)}]*|[#{Regexp.escape(chr)}]*$/, ''
end
end

Which will satisfy the requested requirements:

> "[ [] foo [] boo [][]] ".strip(" []")
=> "foo [] boo"

While still doing what you'd expect in less extreme circumstances.

> ' _bar_ '.strip.strip('_')
=> "bar"


nJoy!

"[[ ] foo [] boo ][ ]".gsub(/\A[ \[\]]+|[ \[\]]+\Z/,'')
=> "foo [] boo"

Can also be shortenend to

"[[ ] foo [] boo ][ ]".gsub(/\A[][ ]+|[][ ]+\Z/,'')
=> "foo [] boo"

Try the [gsub][1] method:

irb(main):001:0> "[foo ]".gsub(/\As+[/,'')
=> "foo ]"

irb(main):001:0> "foo ]".gsub(/s+]\Z/,'')
=> "foo"

etc.


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