Reverse words in a string: Difference between revisions

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----------------------- Robert Frost</pre>
----------------------- Robert Frost</pre>


=={{header|Objeck}}==
<lang objeck>use Collection;

class Reverselines {
function : Main(args : String[]) ~ Nil {
lines := List->New();
lines->AddBack("---------- Ice and Fire ------------");
lines->AddBack("");
lines->AddBack("fire, in end will world the say Some");
lines->AddBack("ice. in say Some");
lines->AddBack("desire of tasted I've what From");
lines->AddBack("fire. favor who those with hold I");
lines->AddBack("");
lines->AddBack("... elided paragraph last ...");
lines->AddBack("");
lines->AddBack("Frost Robert -----------------------");
lines->Rewind();
each(i : lines) {
words := lines->Get()->As(String)->Split(" ");
if(words <> Nil) {
for(j := words->Size() - 1; j > -1; j-=1;) {
IO.Console->Print(words[j])->Print(" ");
};
};
IO.Console->PrintLine();
lines->Next();
};
}
}</lang>

Output:
<pre>------------ Fire and Ice ----------

Some say the world will end in fire,
Some say in ice.
From what I've tasted of desire
I hold with those who favor fire.

... last paragraph elided ...

----------------------- Robert Frost </pre>


=={{header|Perl 6}}==
=={{header|Perl 6}}==

Revision as of 20:52, 22 April 2014

Task
Reverse words in a string
You are encouraged to solve this task according to the task description, using any language you may know.

The task is to reverse the order of all tokens in each of a number of strings and display the result; the order of characters within a token should not be modified.

Example: “Hey you, Bub!” would be shown reversed as: “Bub! you, Hey”

Tokens are any non-space characters separated by spaces (formally, white-space); the visible punctuation forms part of the word within which it is located and should not be modified. You may assume that there are no significant non-visible characters in the input. Multiple or superfluous spaces may be compressed into a single space. Some strings have no tokens, so an empty string (or one just containing spaces) would be the result. Display the strings in order (1st, 2nd, 3rd, ···), and one string per line. (You can consider the ten strings as ten lines, and the tokens as words.)

Input data
             (ten lines within the box)
 line
     ╔════════════════════════════════════════╗
   1 ║  ---------- Ice and Fire ------------  ║
   2 ║                                        ║  ◄─── a blank line here.
   3 ║  fire, in end will world the say Some  ║
   4 ║  ice. in say Some                      ║
   5 ║  desire of tasted I've what From       ║
   6 ║  fire. favor who those with hold I     ║
   7 ║                                        ║  ◄─── a blank line here.
   8 ║  ... elided paragraph last ...         ║
   9 ║                                        ║  ◄─── a blank line here.
  10 ║  Frost Robert -----------------------  ║
     ╚════════════════════════════════════════╝

Applesoft BASIC

<lang ApplesoftBasic>100 DATA"---------- ICE AND FIRE ------------" 110 DATA" " 120 DATA"FIRE, IN END WILL WORLD THE SAY SOME" 130 DATA"ICE. IN SAY SOME " 140 DATA"DESIRE OF TASTED I'VE WHAT FROM " 150 DATA"FIRE. FAVOR WHO THOSE WITH HOLD I " 160 DATA" " 170 DATA"... ELIDED PARAGRAPH LAST ... " 180 DATA" " 190 DATA"FROST ROBERT -----------------------"

200 FOR L = 1 TO 10 210 READ T$ 220 I = LEN(T$) 240 IF I THEN GOSUB 300 : PRINT W$; : IF I THEN PRINT " "; : GOTO 240 250 PRINT 260 NEXT L 270 END

300 W$ = "" 310 FOR I = I TO 1 STEP -1 320 IF MID$(T$, I, 1) = " " THEN NEXT I : RETURN 330 FOR I = I TO 1 STEP -1 340 C$ = MID$(T$, I, 1) 350 IF C$ <> " " THEN W$ = C$ + W$ : NEXT I 360 RETURN </lang>

AWK

<lang AWK>

  1. syntax: GAWK -f REVERSE_WORDS_IN_A_STRING.AWK

BEGIN { 

   text[++i] = "---------- Ice and Fire ------------"
   text[++i] = ""
   text[++i] = "fire, in end will world the say Some"
   text[++i] = "ice. in say Some"
   text[++i] = "desire of tasted I've what From"
   text[++i] = "fire. favor who those with hold I"
   text[++i] = ""
   text[++i] = "... elided paragraph last ..."
   text[++i] = ""
   text[++i] = "Frost Robert -----------------------"
   leng = i
   for (i=1; i<=leng; i++) {
     n = split(text[i],arr," ")
     for (j=n; j>0; j--) {
       printf("%s ",arr[j])
     }
     printf("\n")
   }
   exit(0)

} </lang>

output:

------------ Fire and Ice ----------

Some say the world will end in fire,
Some say in ice.
From what I've tasted of desire
I hold with those who favor fire.

... last paragraph elided ...

----------------------- Robert Frost

C

<lang c>#include <stdio.h>

  1. include <ctype.h>

void rev_print(char *s, int n) { 

       for (; *s && isspace(*s); s++);
       if (*s) {
               char *e;
               for (e = s; *e && !isspace(*e); e++);
               rev_print(e, 0);
               printf("%.*s%s", (int)(e - s), s, " " + n);
       }
       if (n) putchar('\n');

}

int main(void) { 

       char *s[] = {
               "---------- Ice and Fire ------------",
               "                                    ",
               "fire, in end will world the say Some",
               "ice. in say Some                    ",
               "desire of tasted I've what From     ",
               "fire. favor who those with hold I   ",
               "                                    ",
               "... elided paragraph last ...       ",
               "                                    ",
               "Frost Robert -----------------------",
               0
       };
       int i;
       for (i = 0; s[i]; i++) rev_print(s[i], 1);

       return 0;

}</lang> Output is the same as everyone else's.

Common Lisp

<lang lisp>(defun split-and-reverse (str) 

 (labels 
   ((iter (s lst)
      (let ((s2 (string-trim '(#\space) s)))
        (if s2
            (let ((word-end (position #\space s2)))
              (if (and word-end (< (1+ word-end) (length s2)))
                  (iter (subseq s2 (1+ word-end))
                        (cons (subseq s2 0 word-end) lst))
                  (cons s2 lst)))
              lst))))
 (iter str NIL)))

(defparameter *poem* 

 "---------- Ice and Fire ------------
  
  fire, in end will world the say Some
  ice. in say Some 
  desire of tasted I've what From
  fire. favor who those with hold I

  ... elided paragraph last ...

  Frost Robert -----------------------")

(with-input-from-string (s *poem*) 

 (loop for line = (read-line s NIL)
       while line
       do (format t "~{~a~#[~:; ~]~}~%" (split-and-reverse line))))</lang>

Output is the same as everyone else's.

D

<lang d>void main() { 

   import std.stdio, std.string, std.range;

   immutable text =

"---------- Ice and Fire ------------

fire, in end will world the say Some ice. in say Some desire of tasted I've what From fire. favor who those with hold I

... elided paragraph last ...

Frost Robert -----------------------"; 

   writefln("%(%-(%s %)\n%)",
            text.splitLines.map!(r => r.split.retro));

}</lang> The output is the same as the Python entry.

J

Treated interactively:

<lang J> ([:;@|.[:<;.1 ' ',]);._2]0 :0

Ice and Fire ------------ 

 fire, in end will world the say Some
 ice. in say Some
 desire of tasted I've what From
 fire. favor who those with hold I

  ... elided paragraph last ...

 Frost Robert -----------------------

) 

------------ Fire and Ice ----------  
                                      
Some say the world will end in fire,  
Some say in ice.                      
From what I've tasted of desire       
I hold with those who favor fire.     
                                      
... last paragraph elided ...         
                                      
----------------------- Robert Frost

</lang>

Julia

<lang Julia>revstring (str) = join(reverse(split(str, " ")), " ")</lang>

Output:
julia> revstring("Hey you, Bub!")
"Bub! you, Hey"

julia> s = IOBuffer(
"---------- Ice and Fire ------------
 
fire, in end will world the say Some
ice. in say Some
desire of tasted I've what From
fire. favor who those with hold I
 
... elided paragraph last ...
 
Frost Robert -----------------------")

julia>  for line in eachline(s)
          println(revstring(chomp(line)))
        end
------------ Fire and Ice ----------
 
Some say the world will end in fire,
Some say in ice.
From what I've tasted of desire
I hold with those who favor fire.
 
... last paragraph elided ...
 
----------------------- Robert Frost


Mathematica

<lang Mathematica>poem = "---------- Ice and Fire ------------ 

    fire, in end will world the say Some
    ice. in say Some 
    desire of tasted I've what From
    fire. favor who those with hold I
  
    ... elided paragraph last ...
  
    Frost Robert -----------------------";

lines = StringSplit[poem, "\n"]; wordArray = StringSplit[#] & @ lines ; reversedWordArray = Reverse[#] & /@ wordArray ; linesWithReversedWords = 

 StringJoin[Riffle[#, " "]] & /@ reversedWordArray;

finaloutput = StringJoin[Riffle[#, "\n"]] & @ linesWithReversedWords</lang>

Output:
------------ Fire and Ice ----------

Some say the world will end in fire,
Some say in ice.
From what I've tasted of desire
I hold with those who favor fire.

... last paragraph elided ...

----------------------- Robert Frost


Objeck

<lang objeck>use Collection;

class Reverselines { 

 function : Main(args : String[]) ~ Nil {
   lines := List->New();
   lines->AddBack("---------- Ice and Fire ------------");
   lines->AddBack("");
   lines->AddBack("fire, in end will world the say Some");
   lines->AddBack("ice. in say Some");
   lines->AddBack("desire of tasted I've what From");
   lines->AddBack("fire. favor who those with hold I");
   lines->AddBack("");
   lines->AddBack("... elided paragraph last ...");
   lines->AddBack("");
   lines->AddBack("Frost Robert -----------------------");
   
   lines->Rewind();
   each(i : lines) {
     words := lines->Get()->As(String)->Split(" ");
     if(words <> Nil) {      
       for(j := words->Size() - 1; j > -1; j-=1;) {
         IO.Console->Print(words[j])->Print(" ");
       };
     };
     IO.Console->PrintLine();
     lines->Next();
   };
 }

}</lang>

Output: 

------------ Fire and Ice ---------- 

Some say the world will end in fire, 
Some say in ice. 
From what I've tasted of desire 
I hold with those who favor fire. 

... last paragraph elided ... 

----------------------- Robert Frost

Perl 6

<lang>say .words.reverse for q:to/END/.lines;

Ice and Fire ------------

fire, in end will world the say Some ice. in say Some desire of tasted I've what From fire. favor who those with hold I

... elided paragraph last ...

Frost Robert ----------------------- END </lang>

Output:
------------ Fire and Ice ----------

Some say the world will end in fire,
Some say in ice.
From what I've tasted of desire
I hold with those who favor fire.

... last paragraph elided ...

----------------------- Robert Frost

Python

<lang python>>>> text = \

Ice and Fire ------------

fire, in end will world the say Some ice. in say Some desire of tasted I've what From fire. favor who those with hold I

... elided paragraph last ...

Frost Robert ----------------------- >>> for line in text.split('\n'): print(' '.join(line.split()[::-1]))

Fire and Ice ----------

Some say the world will end in fire, Some say in ice. From what I've tasted of desire I hold with those who favor fire.

... last paragraph elided ...

Robert Frost

>>> </lang>

Racket

<lang racket>#lang racket/base

(require racket/string)

(define (split-reverse str) 

 (string-join 
  (reverse 
   (string-split str))))

(define poem 

 "---------- Ice and Fire ------------

fire, in end will world the say Some ice. in say Some desire of tasted I've what From fire. favor who those with hold I

... elided paragraph last ...

Frost Robert -----------------------")


(let ([poem-port (open-input-string poem)]) 

 (let loop ([l (read-line poem-port)])
   (unless (eof-object? l)
     (begin (displayln (split-reverse l))
             (loop (read-line poem-port))))))

</lang>

REXX

<lang rexx>/*REXX pgm reverses the order of tokens in a string, but not the letters*/ @. = @.1 = "---------- Ice and Fire ------------" @.2 = ' ' @.3 = "fire, in end will world the say Some" @.4 = "ice. in say Some" @.5 = "desire of tasted I've what From" @.6 = "fire. favor who those with hold I" @.7 = ' ' @.8 = "... elided paragraph last ..." @.9 = ' ' @.10 = "Frost Robert -----------------------" 

 do   j=1  while  @.j\==;  $=       /*process each "line"; nullify $.*/
   do k=1  for  words(@.j)            /*process each word in the string*/
   $=word(@.j,k) $                    /*prepend the word to a new line.*/
   end   /*k*/                        /* [↑]  could do this another way*/
 say $                                /*display newly constructed line.*/
 end     /*j*/                        /*stick a fork in it, we're done.*/</lang>

output when using the ten lines of input: 

------------ Fire and Ice ----------

Some say the world will end in fire,
Some say in ice.
From what I've tasted of desire
I hold with those who favor fire.

... last paragraph elided ...

----------------------- Robert Frost

Ruby

<lang ruby>def reverse_words(strings) 

 strings.each_line.map {|line| line.split.reverse.join(" ")}

end

str = <<'EOS'

Ice and Fire ------------

fire, in end will world the say Some ice. in say Some desire of tasted I've what From fire. favor who those with hold I

... elided paragraph last ...

Frost Robert ----------------------- EOS

puts reverse_words(str)</lang>

Output is the same as everyone else's.

Tcl

<lang tcl>set lines { 

   "---------- Ice and Fire ------------"
   ""
   "fire, in end will world the say Some"
   "ice. in say Some"
   "desire of tasted I've what From"
   "fire. favor who those with hold I"
   ""
   "... elided paragraph last ..."
   ""
   "Frost Robert -----------------------"

} foreach line $lines { 

   puts [join [lreverse [regexp -all -inline {\S+} $line]]]
   # This would also work for data this simple:
   ### puts [lreverse $line]

}</lang>

Output:
------------ Fire and Ice ----------

Some say the world will end in fire,
Some say in ice.
From what I've tasted of desire
I hold with those who favor fire.

... last paragraph elided ...

----------------------- Robert Frost

Alternatively…

Works with: Tcl version 8.6

<lang tcl>puts [join [lmap line $lines {lreverse $line}] "\n"]</lang>

zkl

<lang zkl>text:=Data(0,String, "---------- Ice and Fire ------------", "", "fire, in end will world the say Some", "ice. in say Some", "desire of tasted I've what From", "fire. favor who those with hold I", "", "... elided paragraph last ...", "", "Frost Robert -----------------------");

text.pump(Data,fcn(s){ 

  s.split(" ").filter().reverse().concat(" ")+"\n" })
  .text.println();</lang>
Output:
------------ Fire and Ice ----------

Some say the world will end in fire,
Some say in ice.
From what I've tasted of desire
I hold with those who favor fire.

... last paragraph elided ...

----------------------- Robert Frost
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