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.

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"

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.

Answer 4

Pyth, 17 15 11 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

Answer 5

Ruby, 31 29 25 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:

Answer 6

Haskell, 31 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.

Answer 7

Bash, 36 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.

Answer 8

05AB1E, 9 bytes

#õKðý'".ø

Try it online!

---

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

Answer 9

JavaScript (ES6), 49 52 58

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(" ")}"`)

Answer 10

Python2, 37

Reduced by 1 byte thanks to @ygramul.

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

Original version:

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

Test cases:

Answer 11

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 -"

Answer 12

Japt -Q, 10 4 bytes

¸f ¸

Try it

Answer 13

Java 8, 43 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
                   |\"",      //     and all quotes
                        " ")  //    with a single space
    .trim()                   //  And remove all leading and trailing spaces
  +'"'                        //  And add the trailing quote
                              // End of method (implicit / single-line return statement)

Answer 14

Octave, 44 bytes

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

Try it online!

Answer 15

Tcl, 69 bytes

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

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Tcl, 79 bytes

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

Try it online!

Answer 16

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

Answer 17

Perl 5, 17 bytes

16 bytes of code + 1 for -p

s/ *("| ) */$1/g

Try it online!

Answer 18

Mathematica, 75 bytes

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

Answer 19

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 20

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 21

k4, 23 bytes

" "/:x@&~~#:'x:" "\:0:0

---

                    0:0  / read from stdin
             x:" "\:     / split string on spaces and assign to x
        ~~#:'            / boolean true where string len>0, bool false otherwise
     x@&                 / x at indices where true
" "/:                    / join with spaces

Answer 22

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 23

Wren, 56 bytes

Wait. The replace only does it once? Now I have to use the split-join combo.

Fn.new{|x|x.trim().split(" ").where{|i|i!=""}.join(" ")}

Try it online!

Explanation

Fn.new{|x|                                             } // New anonymous function with the operand x
          x.trim()                                       // Trim out whitespace from both sides of the string
                  .split(" ")                            // Split the string into space-separated chunks
                             .where{|i|i!=""}            // Keep all of those that aren't the null string (due to two consecutive spaces)
                                             .join(" ")  // Join the replaced list together

Answer 24

GolfScript, 8 bytes

' '%' '*

Try it online!

Explanation

The logic is quite simple:

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

Answer 25

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 26

Cobra - 68

As an anonymous function:

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

Answer 27

Objective-C 215

-(NSString*)q:(NSString*)s{NSArray*a=[s componentsSeparatedByString:@" "];NSMutableString*m=[NSMutableString new];for(NSString*w in a){if(w.length){[m appendFormat:@"%@ ",w];}}return[m substringToIndex:m.length-1];}

Uncompressed version:

-(NSString*)q:(NSString*)s{
    NSArray *a=[s componentsSeparatedByString:@" "];
    NSMutableString *m=[NSMutableString new];
    for (NSString *w in a) {
        if (w.length) {
            [m appendFormat:@"%@ ",w];
        }
    }
    return[m substringToIndex:m.length-1];
}

Answer 28

Bash ,14 bytes

read f;echo $f       # assume f="this  is  a    string   "

Answer 29

Python2, 28 Bytes

lambda s:" ".join(s.split())

---

Explanation

lambda s

Anonymous function which takes as input s.

s.split()

Returns a list of the words (which are separated by arbitrary strings of whitespace characters) of the string s.

" ".join(...)

Joins list back into a string, with each word separated by a space (" ").