Stripping off extra spaces from a string

Question

You are given a string. Output the string with one space per words.

Challenge

Input will be a string (not null or empty), surrounded with quotes(") sent via the stdin. Remove leading and trailing spaces from it. Also, if there are more than one space between two words (or symbols or whatever), trim it to just one space. Output the modified string with the quotes.

Rules

• The string will not be longer than 100 characters and will only contain ASCII characters in range (space) to ~(tilde) (character codes 0x20 to 0x7E, inclusive) except ",i.e, the string will not contain quotes(") and other characters outside the range specified above. See ASCII table for reference.
• You must take input from the stdin( or closest alternative ).
• The output must contain quotes(").
• You can write a full program, or a function which takes input (from stdin), and outputs the final string

Test Cases

"this is a string " --> "this is a string"
" blah blah blah " --> "blah blah blah"
"abcdefg" --> "abcdefg"
" " --> ""
"12 34 ~5 6 (7, 8) - 9 - " --> "12 34 ~5 6 (7, 8) - 9 -" 

Scoring

This is code golf, so the shortest submission (in bytes) wins.

• blutorange: You say must take input from stdin, and later you say ...or a function which takes input, and outputs the final string. Does this mean the function must take input from stdin as well?
• Spikatrix: @blutorange , Yes. Edited to clarify it.
• edc65: " "aa" " --> ""aa"" (are quotes valid inside the input string?)
• Spikatrix: @edc65 , Good point. The answer to that is no. Edited to clarify it.
• manatwork: Some answers are processing string including the double quotes: " this ", others process a once double quoted string which reaches the code with the double quotes already stripped off: ` this `. This way the answers and the languages'/authors' efficiencies are not really comparable. @CoolGuy, could you firmly clarify the requirement on this?

Answer 1

CJam, 7 bytes

q~S%S*p

Code Explanation

CJam has reserved all capital letters as inbuilt variables. So S has a value of a space here.

q~ e# Read the input (using q) and evaluate (~) to get the string
 S% e# Split on running lengths (%) of space
 S* e# Join (*) the splitted parts by single space
 p e# Print the stringified form (p) of the string.

This removes the trailing and leading spaces as well

Try it online here

Answer 2

///: 18 characters

/ / //" /"// "/"/

Sample run:

(Using faubiguy's interpreter from his Perl answer for Interpret /// (pronounced 'slashes').)

bash-4.3$ ( echo -n '/ / //" /"// "/"/'; echo '" foo * bar "'; ) | slashes.pl
"foo * bar"

• r3mainer: Haven't I seen this program somewhere before?
• Martin Ender: Technically you're not taking input though. ;) There's this language but reading input is still quite a pain I think.

Answer 3

Perl, 22

(20 bytes of code, plus 2 command line switches)

s/ +/ /g;s/" | "/"/g

Needs to be run with the -np switch so that $_ is automatically filled via stdin and printed to stdout. I'm going to assume this adds 2 to the byte count.

• izabera: same solution: sed -E 's/ +/ /g;s/" | "/"/g'
• Martin Ender: The same thing is 12 bytes in Retina. :)
• user62131: -p implies -n, so you only have to take a +1 penalty here (assuming you don't just switch to a different language, like the other commenters suggest).

Answer 4

Bash, (削除) 36 (削除ここまで) 32 bytes

As a function, a program, or just in a pipe:

xargs|xargs|xargs -i echo '"{}"'

Explanation

The first xargs strips the quotation marks.

The second xargs trims the left side and replaces multiple adjacent spaces in the middle of the string with one space by taking each "word" and separating each with a space.

The xargs -i echo '"{}"' trims the right side and rewraps the resulting string in double quotes.

• manatwork: Wow! That is tricky. Unfortunately not handles test case 4, but still impressing.
• Deltik: Yeah, this code meets the fourth test case and is shorter.
• Cyoce: Can you do something like this? x=xargs;$x|$x|$x -i echo '"{}"'
• Deltik: @Cyoce: You could indeed do that to save one byte at the cost of losing pipe functionality. Still not as short as this solution and still doesn't satisfy the fourth test case.

Answer 5

Ruby, (削除) 31 (削除ここまで) (削除) 29 (削除ここまで) (削除) 25 (削除ここまで) 23 Bytes

p$*[0].strip.squeeze' '

Code Explanation:

• p outputs string within double quotes to STDOUT (There's more to it though...)
• $* is an array of STDIN inputs, $*[0] takes the first one
• strip removes starting and ending spaces
• squeeze ' ' replaces>1 space characters with a single space

Test Cases:

enter image description here

• DickieBoy: You can replace ARGV with $* saving two bytes. gsub /\s+/, ' ' can be replaced with squeeze ' ' for another 4 bytes
• Sheharyar: @DickieBoy, thank you for $*, I didn't know that. But we can't replace gsub /\s+/, ' ' with squeeze because they are not the same.
• DickieBoy: What do you mean by "are not the same"? The outputs are the same.
• DickieBoy: squeeze ' ' will only squeeze spaces. "yellow moon".squeeze "l" => "yelow moon"
• manatwork: Personally I am. And some of other answerers too. But as I see, neither you are alone with your interpretation... A clarification from the question owner would be welcome. By the way, both the space between p and its parameter and squeeze and its parameter are unnecessary.

Answer 6

Pyth, (削除) 17 (削除ここまで) (削除) 15 (削除ここまで) (削除) 11 (削除ここまで) 10 bytes

(thanks to Ypnypn and FryAmTheEggman)

pjd-cQdkNN

Could probably be golfed more.

If the output can use ' instead of " then I only need 8 bytes:

`jd-cQdk

• Ypnypn: You can use N instead of \"
• izzyg: Welcome to Pyth, Tylio. The second program could be shorterned by the use of d.
• Tyilo: @isaacg haven't I already used d for everything it can be used for?
• izzyg: @Tyilo I think you made an edit at about the same time I commented. It's all good now.
• FryAmTheEggman: You can use p to save a few bytes on string concatenation instead of many +es. pjd-cQdkNN

Answer 7

Haskell, (削除) 31 (削除ここまで) 25 bytes

fmap(unwords.words)readLn

words splits the string into a list of strings with spaces as delimiters and unwords joins the list of strings with a single spaces in-between. The quotes " are stripped of and put back by Haskell's read and show (implicitly via the REPL) functions on strings.

Outputting by the function itself is three bytes longer, i.e. 28 bytes:

print.unwords.words=<<readLn

Edit: @Mauris pointed to the readLn function, which saved some bytes.

• Spikatrix: I'm getting Parse error: naked expression at top level when I tested both the codes here
• nimi: @CoolGuy: rextester.com expects whole programs, not functions, so try main=interact$show.unwords.words.read. There's an online REPL at the frontage of haskell.org (requires cookies enabled) where you can try fmap(unwords.words.read)getLine.
• lynn: fmap(unwords.words)readLn and print.unwords.words=<<readLn are a bit shorter.

Answer 8

JavaScript (ES6), 49 (削除) 52 58 (削除ここまで)

Edit 6 bytes shorter, thanks to @Optimizer

Edit 2 -3, thanks to @nderscore

Input/output via popup. Using template string to cut 1 byte in string concatenation.

Run snippet to test in Firefox.

alert(`"${prompt().match(/[^ "]+/g).join(" ")}"`)

• Optimizer: alert(`"${eval(prompt()).match(/\S+/g).join(" ")}"`) - 52
• edc65: @Optimizer thx. Note, that just works after the last clarification about the quotes: eval('" " "') would crash.
• Spikatrix: When I tested the fourth test case (using chrome), no popup (which shows the result) is seen. Why?
• edc65: @CoolGuy maybe because Chrome does not run ES6? I never test ES6 with Chrome. Anyway I tried it now in my Chrome (42.0.2311.152) and works for me.
• nderscore: -3: alert(`"${prompt().match(/[^ "]+/g).join(" ")}"`)

Answer 9

R, 45 bytes

cat('"',gsub(" +"," ",readline()),'"',sep="")

The readline() function reads from STDIN, automatically stripping any leading and trailing whitespace. Excess space between words is removed using gsub(). Finally, double quotes are prepended and appended and the result is printed to STDOUT.

Examples:

> cat('"',gsub(" +"," ",readline()),'"',sep="")
 This is a string 
"This is a string"
> cat('"',gsub(" +"," ",readline()),'"',sep="")
12 34 ~5 6 (7, 8) - 9 - 
"12 34 ~5 6 (7, 8) - 9 -"

• MickyT: Not sure if it complies totally with the rules, but the cat may not be totally required, just the gsub. The output from that is [1] "This is a string"
• Alex A.: @MickyT: Thanks for the suggestion. My interpretation based on the OP's comment (first on the post) was that it had to be printed to stdout. I'll ask for clarification.
• MickyT: Ahhh ... didn't see that comment or requirement

Answer 10

Python2, 37

Reduced by 1 byte thanks to @ygramul.

print'"%s"'%' '.join(input().split())

Original version:

print'"'+' '.join(input().split())+'"'

Test cases:

Test cases screenshot

• mbomb007: I really wanted to use print" ".join(raw_input().split()), but it would have a trailing space inside the last quotation mark if there were spaces after the last word...
• ygramul: You can shave off an extra byte using % formatting: print'"%s"'%' '.join(input().split())

Answer 11

05AB1E, 9 bytes

#õKðý'".ø

Try it online!

---

# | Split on spaces.
 õK | Remove empty Strings.
 ðý | Join with spaces.
 '".ø | Surround with quotes.

Answer 12

Java 8, 40 bytes

s->'"'+s.replaceAll(" +"," ").trim()+'"'

Explanation:

Try it here.

s-> // Method with String as parameter and return-type
 '"' // Return a leading quote
 +s.replaceAll(" +", // + Replace all occurrences of multiple spaces in the input
 " ") // with a single space
 .trim() // and remove all leading and trailing spaces
 +'"' // + a trailing quote

Answer 13

Mathematica, 75 bytes

a=" ";b=a...;Print[InputString[]~StringReplace~{b~~"\""~~b->"\"",a..->a}]

Answer 14

KDB(Q), 28 bytes

" "sv except[;enlist""]" "vs

Explanation

 " "vs / cut string by space
 except[;enlist""] / clear empty strings
" "sv / join back with space

Test

q)" "sv except[;enlist""]" "vs"12 34 ~5 6 (7, 8) - 9 - "
"12 34 ~5 6 (7, 8) - 9 -"

Answer 15

Octave, 44 bytes

@(x)[34 strjoin(regexp(x,'\S+','match')) 34]

Try it online!

Answer 16

Perl 5, 17 bytes

16 bytes of code + 1 for -p

s/ *("| ) */1ドル/g

Try it online!

Answer 17

Powershell, 40 bytes

"`"$(($args-Replace' +'," ").trim())`""

Pretty straight forward and not very impressive.

Explanation

Take input parameter via (predfined) args-variable, replace all multiple spaces with one, trim leading and trailing spaces using trim()-method, add quotes. Powershell will print strings to console as default behavior.

Answer 18

Jq 1.5, 42 bytes

split(" ")|map(select(length>0))|join(" ")

Sample Run

$ jq -M 'split(" ")|map(select(length>0))|join(" ")' < data
"this is a string"
"blah blah blah"
"abcdefg"
""
"12 34 ~5 6 (7, 8) - 9 -"
$ echo -n 'split(" ")|map(select(length>0))|join(" ")' | wc -c
 42

Try it online

• jq170727: I caught the output issue earlier (see edit 5) but didn't notice the input issue. The command is fixed now. Thanks!

Answer 19

Tcl, 69 bytes

puts [string map {{ "} \" {" } \"} [regsub -all \ + [gets stdin] \ ]]

Try it online!

(削除)

Tcl, 79 bytes

puts \"[string trim [regsub -all \ + [string range [gets stdin] 1 end-1] \ ]]\"

Try it online!

(削除ここまで)

• sergiol: @KevinCruijssen Fixed. unfortunately, at the expense of many bytes. Tks for telling me.

Answer 20

Japt -Q, (削除) 10 (削除ここまで) 4 bytes

 ̧f ̧

Try it

Answer 21

Zsh, 15 bytes

<<<\"${(Qz)1}\"

Try it online!

Input string contains embedded quotes. Remove the Q for 14 bytes if the input string does not contain embedded quotes, as is done in some of the other answers here.

Parameter expansion flags: Q dequotes, then z splits into words as the shell does. The words are then implicitly joined by spaces.

Answer 22

GolfScript, 8 bytes

' '%' '*

Try it online!

Explanation

The logic is quite simple:

' '% # Split on spaces, remove empty results
 ' '* # Join on spaces

Answer 23

Nim, 72 bytes

import strutils
echo'"',stdin.readAll[1..^2].splitWhitespace.join" ",'"'

Try it online!

Ignoring the IO restrictions as many answers do, 58 bytes:

import strutils
echo stdin.readAll.splitWhitespace.join" "

Try it online!

Answer 24

C (gcc), 82 bytes

char*s=&s+9;main(t){for(gets(s);*s;s++)*s>32|(s[1]>32&&s[2]&&t)&&putchar(*s,--t);}

Try it online!

Answer 25

K (ngn/k), (削除) 21 (削除ここまで) (削除) 18 (削除ここまで) (削除) 16 (削除ここまで) 15 bytes

" "/(~#:')_" "\

Try it online!

• " "\ split (implicit) input on spaces
• (~#:')_ drop empty strings
• " "/ join remaining items with spaces

Answer 26

Fortran, 113 bytes

Try it Online!

character(99)S;read(*,'(A)')S;S='"'//trim(adjustl(S))//'"'
do i=1,99;if(S(i:i+1)>' ')call fput(S(i:i));enddo;end

Per wikibooks, "It should be remembered that Fortran is designed for scientific computing and is probably not a good choice for writing a new word processor."

Fortran doesn't have a regex concept either. This just makes string challenges more interesting!

In this solution, we trim the string S, then iterate over it. Print each character unless it's a space followed by another space.

Previously: (削除) 127 bytes (削除ここまで), (削除) 147 bytes (削除ここまで)

• roblogic: Other ideas failed! print* always prints a leading space and a new line. Writing to a new string (avoiding formatting directives) is annoying because gfortran fills it with garbage! Sigh
• roblogic: ...but fput is awesome.

Answer 27

ARBLE, 26 bytes

join(explode(s,"%S+")," ")

explode groups by non-spaces, and then join re-concatenates them.

Try it online!

Answer 28

Thunno 2, 4 bytes

OðjṘ

Try it online!

Explanation

OðjṘ # Implicit input
 # Implicit eval to
 # remove the quotes
O # Split on spaces
 ðj # Join on spaces
 Ṙ # Repr (surround
 # by quotes)
 # Implicit output

Answer 29

golfua, 42 bytes

L=I.r():g('%s*\"%s*','"'):g('%s+',' ')w(L)

Simple pattern matching replacement: find any double quotes (\") surrounded by 0 or more spaces (%s*) & return the single quote, then replace all 1 or more spaces (%s+) with a single space.

A Lua equivalent would be

Line = io.read()
NoSpaceQuotes = Line:gsub('%s*\"%s*', '"')
NoExtraSpaces = NoSpaceQuotes:gsub('%s+', ' ')
print(NoExtraSpaces)

Answer 30

Cobra - 68

As an anonymous function:

do
 print'"[(for s in Console.readLine.split where''<s).join(' ')]"'