Sort the letters of string in alphabetical order

Revision as of 17:09, 24 July 2021 by rosettacode>Gerard Schildberger (→‎{{header|REXX}}: added wording to the REXX section header.)

Write a function to sort the characters of a string in alphabetical order.

Sort the letters of string in alphabetical order is a draft programming task. It is not yet considered ready to be promoted as a complete task, for reasons that should be found in its talk page.
Task

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The case   (uppercase and lowercase)   of any letters should be preserved.

Write the function even your language has a built-in function for it.

Go

As in the case of the Wren entry, we write a function to bubble sort the characters of a string since this method is not, of course, used in Go's standard 'sort' package. <lang go>package main

import (

   "fmt"
   "strings"

)

func bubbleSort(s string) string {

   chars := []rune(s)
   n := len(chars)
   for {
       n2 := 0
       for i := 1; i < n; i++ {
           if chars[i-1] > chars[i] {
               tmp := chars[i]
               chars[i] = chars[i-1]
               chars[i-1] = tmp
               n2 = i
           }
       }
       n = n2
       if n == 0 {
           break
       }
   }
   return string(chars)

}

func main() {

   s := "forever go programming language"
   s = bubbleSort(s)
   s = strings.TrimLeft(s, " \t") // get rid of whitespace which will be at the front
   fmt.Println(s)

}</lang>

Output:
aaaeeefgggggilmmnnoooprrrruv

REXX

For REXX, it is normally faster to convert an string of characters to a one─character array of characters,
sort the array,   and then convert the array back to a (simple) string.

A simple bubble sort is used for this example.

The particular string used is from a typing drill devised by Charles E. Weller in the early 20th century. <lang rexx>/*REXX program sorts an array (of any kind of items) using the bubble─sort algorithm.*/ parse arg y /*generate the array elements (items).*/ if y= then y= "Now is the time for all good men to come to the aid of their country."

            say 'before sort: ───►'y"◄───"      /*show the  before string of characters*/

call make@ y /*convert a string into an array (@.) */ call bSort # /*invoke the bubble sort with # items.*/ call makeS /*convert an array (@.) into a string. */

            say ' after sort: ───►'$"◄───"      /*show the  before string of characters*/

exit 0 /*stick a fork in it, we're all done. */ /*──────────────────────────────────────────────────────────────────────────────────────*/ bSort: procedure expose @.; parse arg n /*N: is the number of @ array elements.*/

        do m=n-1  by -1  until ok;        ok= 1 /*keep sorting the  @ array until done.*/
          do j=1  for m;  k= j+1;  if @.j<=@.k  then iterate      /*elements in order? */
          _= @.j;  @.j= @.k;  @.k= _;     ok= 0 /*swap two elements;  flag as not done.*/
          end   /*j*/
        end     /*m*/;               return

/*──────────────────────────────────────────────────────────────────────────────────────*/ make@: parse arg z; #= length(z); do j=1 for #; @.j= substr(z, j, 1); end; return makeS: parse arg a; $=; do j=1 for #; $= $ || @.j; end; return</lang>

output   when using the default input:
before sort: ───►Now is the time for all good men to come to the aid of their country.◄───
 after sort: ───►               .Naaccddeeeeeeffghhhiiiillmmmnnooooooooorrrstttttttuwy◄───

Ring

<lang ring> see "working..." + nl see "Sort the letters of string in alphabitical order:" + nl str = "forever ring programming language" see "Input: " + str + nl

for n = 1 to len(str)-1

   for m = n+1 to len(str)
       if ascii(str[n]) > ascii(str[m])
          temp = str[n]
          str[n] = str[m]
          str[m] = temp
       ok
   next

next

str = substr(str," ","") see "Output: " + str + nl see "done..." + nl </lang>

Output:
working...
Sort the letters of string in alphabitical order:
Input: forever ring programming language
Output: aaaeeefgggggiilmmnnnooprrrrruv
done...

Wren

Well, we'll write a function for a bubble sort which we don't have in Wren-sort because it's normally much slower than the other methods. However, it's fast enough here. <lang ecmascript>var bubbleSort = Fn.new { |s|

   var chars = s.toList
   var n = chars.count
   while (true) {
       var n2 = 0
       for (i in 1...n) {
           if (chars[i - 1].codePoints[0] > chars[i].codePoints[0]) {
               chars.swap(i, i - 1)
               n2 = i
           }
       }
       n = n2
       if (n == 0) break
   }
   return chars.join()

}

var s = "forever wren programming language" s = bubbleSort.call(s).trimStart() // get rid of whitespace which will be at the front System.print(s)</lang>

Output:
aaaeeeefggggilmmnnnooprrrrruvw