Ruby function to remove all white spaces?

ruby string

What is the Ruby function to remove all white spaces? I'm looking for something kind of like PHP's trim()?

Your question is not clear: Do you want to remove all whitespace or do you want to get rid of leading and trailing whitespace?

PHP's trim() strips whitespace "from the beginning and end of a string" (as stated within documentation), it does not remove "all whitespaces".

When in doubt, look at the Ruby online documentation for the String class (see .strip below).

Note that all answers using String#strip or matching /\s+/ will remove only ASCII whitespace. If you want to ensure any non-ASCII whitespace is captured too (e.g. HTML's &nbsp) see the oddly unpopular answer from @EBooker.

Pity that such great answers cannot get the final dignity of one being accepted

joel.neely

If you want to remove only leading and trailing whitespace (like PHP's trim) you can use .strip, but if you want to remove all whitespace, you can use .gsub(/\s+/, "") instead .

Does "/\s+/" simple mean whitespace?

\s+ means 1 or more whitespace characters (space, newline, tab). The // surrounding show that it's a regular expression.

This is not equivalent to trim()

strip was exactly what i was looking for, thanks for good question and awnser!

@BrettHolt The gsub expression is not the same as trim, but the questioner included the phrase "all whitespace", which isn't the same as trim either. So I gave alternatives.

Ed S.

s = "I have white space".delete(' ')

And to emulate PHP's trim() function:

s = "   I have leading and trailing white space   ".strip

this is much more readable than the regex, why is it not as popular?

@ckarbass: Because many people prefer overly complex solutions to simple problems. It goes away with experience.

@ckarbass @Ed S. It isn't as popular because it isn't the same. The original question used the phrase "all whitespace", which includes tabs, newlines, etc. This proposed answer will not remove those other whitespace characters. As for "overly complex", I suggest comparing the simple regular expression to .delete(' ').delete('\t').delete('\n') ..., which is overly verbose and provides many opportunities for typos and errors of omission.

@joel.neely: I answered this question a long time ago, but read the question again, this time more carefully. The OP asked for "a function to remove all whitespace", but then asked for "something like PHP's trim()". So, it's a bit difficult to know exactly what they want here. trim() certainly does not remove newlines and other whitespace characters. You're choosing one interpretation of a vague question.

@joel.neely: That said, I agree that a solution which goes beyond the literal interpretation of the question is a better one in this case (i.e., a regex removing all characters which would constitute whitespace rather than a string of delete() calls.)

John Topley

String#strip - remove all whitespace from the start and the end.

String#lstrip - just from the start.

String#rstrip - just from the end.

String#chomp (with no arguments) - deletes line separators (\n or \r\n) from the end.

String#chop - deletes the last character.

String#delete - x.delete(" \t\r\n") - deletes all listed whitespace.

String#gsub - x.gsub(/[[:space:]]/, '') - removes all whitespace, including unicode ones.

Note: All the methods above return a new string instead of mutating the original. If you want to change the string in place, call the corresponding method with ! at the end.

The String#delete example appears to use a regex, but \s is in quotes instead of slashes. Also I couldn't find any mention in the documentation that delete can take a regex as an argument.

@slothbear, it's not a regex, it's a small set of patterns that resemble regexes. As for the documentation #delete is said to work similarly to #count. You can try it in the console as well.

Thanks for teaching me something new. And also thanks for the reminder to try things in the smallest possible context (command line).

@SeinopSys I wanted to keep this answer Ruby only.

Only the final example in this answer catches the dread ASCII 160 'non-breaking space', the bane of web scrapers. #strip does not. See stackoverflow.com/questions/4859438/…

jrhicks

Related answer:

"   clean up my edges    ".strip

returns

"clean up my edges"

That's the one I forgot about. I knew there was a method to remove whitespace which would do so by default if no arguments were passed. +1

This is equivalent to trim. Please refer to the quote from @Tadeck above.

If there is a possibility that the variable is nil, be sure to run .to_s method before running strip so that the strip method does not raise an error. Ex. str=nil; str.to_s.strip #=> ""

I prefer some_data.strip! if some_data.is_a? String

Felix

If you are using Rails/ActiveSupport, you can use squish method. It removes white space on both ends of the string and groups multiple white space to single space.

For eg.

" a  b  c ".squish

will result to:

"a b c"

Check this reference from api.rubyonrails.org.

Note that link-only answers are discouraged, SO answers should be the end-point of a search for a solution (vs. yet another stopover of references, which tend to get stale over time). Please consider adding a stand-alone synopsis here, keeping the link as a reference.

I think this answer was enough explained and the fact that link was reference since the answer itself was clear explained. This function was good, thanks

This is from ActiveSupport. You don't need all of Rails to use it, but you do need at least ActiveSupport and a require 'active_support/core_ext/string/filters'

To be clear, this is any whitespace. E.g. "a \t \n \f \r \v b".squish == "a b"

Arturo Herrero

"1232 23 2 23 232 232".delete(' ')
=> "123223223232232"

Delete works faster =)

user         system     total      real
gsub, s      0.180000   0.010000   0.190000 (0.193014)
gsub, s+     0.200000   0.000000   0.200000 (0.196408)
gsub, space  0.220000   0.000000   0.220000 (0.222711)
gsub, join   0.200000   0.000000   0.200000 (0.193478)
delete       0.040000   0.000000   0.040000 (0.045157)

but this removes only spaces, not all white spaces

delete(" \t\r\n") will take care of typical whitespace, and is still faster than gsub.

scarver2

Ruby's .strip method performs the PHP equivalent to trim().

To remove all whitespace:

"  leading    trailing   ".squeeze(' ').strip
=> "leading trailing"

@Tass made me aware that my original answer removes duplicate letters in succession - YUCK! I've since switched to the squish method which is smarter about such occurrences if using the Rails framework.

require 'active_support/all'
"  leading    trailing   ".squish
=> "leading trailing"

"  good    men   ".squish
=> "good men"

Cite: http://apidock.com/rails/String/squish

This will remove "joined" duplicate characters. "good men".squeeze.strip will return "god men"

Thanks for pointing that out @Tass. I've edited my answer in favor of the squish method.

+1 for "duplicate letters in succession." I couldn't come up with a way to describe the scenario. Well done! :-)

Jules Copeland

It's a bit late, but anyone else googling this page might be interested in this version -

If you want to clean up a chunk of pre-formatted text that a user may have cut & pasted into your app somehow, but preserve the word spacing, try this:

content = "      a big nasty          chunk of     something

that's been pasted                        from a webpage       or something        and looks 

like      this

"

content.gsub(/\s+/, " ").strip

#=> "a big nasty chunk of something that's been pasted from a webpage or something and looks like this"

One could also use Rails' squish method: apidock.com/rails/String/squish

Or if you don't have Rails, and you don't have newlines, squeeze(" ") might work.

Sapphire_Brick

To remove whitespace on both sides:

Kind of like php's trim()

"   Hello  ".strip

To remove all spaces:

"   He    llo  ".gsub(/ /, "")

To remove all whitespace:

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

Kevin

" Raheem Shaik ".strip

It will removes left & right side spaces. This code would give us: "Raheem Shaik"

Community

split.join will blast all spaces anywhere in the string.

"  a b  c    d     ".split.join
> "abcd"

It's easy to type and remember, so it's nice on the console and for quick hacking. Arguably not welcome in serious code though as it masks the intent.

(Based on Piotr's comment in Justicle's answer above.)

Many, many thanks for this comment :-) This is the only method that works if you have long string which looks like a paragraph.

Justicle

Also don't forget:

$ s = "   I have white space   ".split
=> ["I", "have", "white", "space"]

So s.split.join will do the job.

This is nice when iterating: [" Hello World", "Big Giraffe "].map(&:split).map(&:join) #=> ["HelloWorld", "BigGiraffe"]

EBooker

You Could try this

"Some Special Text Values".gsub(/[[:space:]]+/, "")

using :space: removes non breaking space along with regular space.

This is actually the best answer IMHO, as in the wild HTML &nbsp and any other non-ASCII whitespaces will not be removed by String#strip or matched by /\s/. See the section entitled "POSIX bracket expressions" in the Regexp docs

euccas

Use gsub or delete. The difference is gsub could remove tabs, while delete cannot. Sometimes you do have tabs in files which are added by the editors.

a = "\tI have some whitespaces.\t"
a.gsub!(/\s/, '')  #=>  "Ihavesomewhitespaces."
a.gsub!(/ /, '')   #=>  "\tIhavesomewhitespaces.\t"
a.delete!(" ")     #=>  "\tIhavesomewhitespaces.\t"
a.delete!("/\s/")  #=>  "\tIhavesomewhitespaces.\t"
a.delete!('/\s/')  #=>  using single quote is unexpected, and you'll get "\tI have ome whitepace.\t"

bdbasinger

The gsub method will do just fine. The gsub method can be called on a string and says:

a = "this is a string"
a = a.gsub(" ","")
puts a
#Output: thisisastring

The gsub method searches for every occurrence of the first argument and replaces it with the second argument. In this case, it will replace every space within the string and remove it.

Another example:

b = "the white fox has a torn tail"

Let's replace every occurrence of the letter " t " with a capital " T "

b = b.gsub("t","T")
puts b 
#Output: The whiTe fox has a Torn Tail

edikgat

"asd sda sda sd".gsub(' ', '')
=> "asdsdasdasd"

but this removes only spaces, not all white spaces

Michael Gaskill

For behavior exactly matching PHP trim, the simplest method is to use the String#strip method, like so:

string = "  Many have tried; many have failed!    "
puts "Original [#{string}]:#{string.length}"
new_string = string.strip
puts "Updated  [#{new_string}]:#{new_string.length}"

Ruby also has an edit-in-place version, as well, called String.strip! (note the trailing '!'). This doesn't require creating a copy of the string, and can be significantly faster for some uses:

string = "  Many have tried; many have failed!    "
puts "Original [#{string}]:#{string.length}"
string.strip!
puts "Updated  [#{string}]:#{string.length}"

Both versions produce this output:

Original [  Many have tried; many have failed!    ]:40
Updated  [Many have tried; many have failed!]:34

I created a benchmark to test the performance of some basic uses of strip and strip!, as well as some alternatives. The test is this:

require 'benchmark'

string = 'asdfghjkl'
Times = 25_000

a = Times.times.map {|n| spaces = ' ' * (1+n/4); "#{spaces}#{spaces}#{string}#{spaces}" }
b = Times.times.map {|n| spaces = ' ' * (1+n/4); "#{spaces}#{spaces}#{string}#{spaces}" }
c = Times.times.map {|n| spaces = ' ' * (1+n/4); "#{spaces}#{spaces}#{string}#{spaces}" }
d = Times.times.map {|n| spaces = ' ' * (1+n/4); "#{spaces}#{spaces}#{string}#{spaces}" }

puts RUBY_DESCRIPTION
puts "============================================================"
puts "Running tests for trimming strings"

Benchmark.bm(20) do |x|
  x.report("s.strip:")                 { a.each {|s| s = s.strip } }
  x.report("s.rstrip.lstrip:")         { a.each {|s| s = s.rstrip.lstrip } }
  x.report("s.gsub:")                  { a.each {|s| s = s.gsub(/^\s+|\s+$/, "") } }
  x.report("s.sub.sub:")               { a.each {|s| s = s.sub(/^\s+/, "").sub(/\s+$/, "") } }

  x.report("s.strip!")                 { a.each {|s| s.strip! } }
  x.report("s.rstrip!.lstrip!:")       { b.each {|s| s.rstrip! ; s.lstrip! } }
  x.report("s.gsub!:")                 { c.each {|s| s.gsub!(/^\s+|\s+$/, "") } }
  x.report("s.sub!.sub!:")             { d.each {|s| s.sub!(/^\s+/, "") ; s.sub!(/\s+$/, "") } }
end

These are the results:

ruby 2.2.5p319 (2016-04-26 revision 54774) [x86_64-darwin14]
============================================================
Running tests for trimming strings
                           user     system      total        real
s.strip:               2.690000   0.320000   3.010000 (  4.048079)
s.rstrip.lstrip:       2.790000   0.060000   2.850000 (  3.110281)
s.gsub:               13.060000   5.800000  18.860000 ( 19.264533)
s.sub.sub:             9.880000   4.910000  14.790000 ( 14.945006)
s.strip!               2.750000   0.080000   2.830000 (  2.960402)
s.rstrip!.lstrip!:     2.670000   0.320000   2.990000 (  3.221094)
s.gsub!:              13.410000   6.490000  19.900000 ( 20.392547)
s.sub!.sub!:          10.260000   5.680000  15.940000 ( 16.411131)

Saurabh Thakur

A lot of suggestions work here, but when I read your question and the specific line saying "removing all the whitespace", what came to my mind was this:

" a b c " => "abc"

And if that is really what is required, you can do this simple operation

wide_string = " a b c "

narrow_string = wide_string.delete(" ")

# you can pass all the different kinds 
# of whitespaces that you want to remove

puts narrow_string # => "abc"

Jeremy Gunter

My personal preference is using the method .tr

as in:

string = "this is a string to smash together"

string.tr(' ', '') # => "thisisastringtosmashtogether"

Thanks to @FrankScmitt for pointing out that to make this delete all whitespace(not just spaces) you would need to write it as such:

string = "this is a string with tabs\t and a \nnewline"

string.tr(" \n\t", '') # => "thisisastringwithtabsandanewline"

but this removes only spaces, not all white spaces

To remove all white spaces (space, tab, newline), consider using s.tr(" \t\n", '') instead.

@Gavriel - I misread/misunderstood the question, thank you for pointing that out.

@FrankSchmitt I added your correction to my answer, to more properly answer the OP's question. Thank you for correcting me.

Brad

I was trying to do this as I wanted to use a records "title" as an id in the view but the titles had spaces.

a solution is:

record.value.delete(' ') # Foo Bar -> FooBar

Melanie Shebel

I'm a bit late to the game, but I remove trailing and leading whitespaces by using strip!. If you have an array, such as I did, I needed to iterate through the array and save it after the instance ended. The ! took care of this. This removed all whitespaces at the end or the beginning, not just the first leading or the last trailing.

For example:

array = ["hello ","   Melanie", "is", " new ", "to  ", " programming"]
array.each do |i|
  i.strip!
end

This would output to: ["hello","Melanie", "is", "new ", "to", "programming"]. I further explored/shared this in a video I made to highlight this code for similar question I had.

I'm newer to programming and using strip did not work as it didn't save it to the array after the loop ended.

Artur Okoński

I would use something like this:

my_string = "Foo bar\nbaz quux"

my_string.split.join
=> "Foobarbazquux"

straight forward. Thanks

AMIC MING

Ruby's .scan() and .join() methods of String can also help to overcome whitespace in string.

scan(/\w+/).join will remove all spaces and join the string

string = "White spaces in me".scan(/\w+/).join
=>"Whitespacesinme"

It is also removing space from left and right part of the string. Means ltrim, rtrim and trim. Just in case if someone has background over C, FoxPro or Visual Basic and jump in Ruby.

2.1.6 :002 > string = " White spaces in me ".scan(/\w+/).join => "Whitespacesinme" 2.1.6 :003 > string = " White spaces in me".scan(/\w+/).join => "Whitespacesinme" 2.1.6 :004 > string = "White spaces in me ".scan(/\w+/).join => "Whitespacesinme" 2.1.6 :005 >

@AmitPandya Thank you so much for pointing out additional key points of .scan() method. Appreciated !!!

LvcasX1

You can try this:

"ab c d efg hi ".split.map(&:strip)

in order to get this:

["ab, "c", "d", "efg", "hi"]

or if you want a single string, just use:

"ab c d efg hi ".split.join

Ruby function to remove all white spaces?

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