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Programming-Idioms

  • Ada
  • JS
  • Fortran
  • Lisp

Idiom #274 Remove all white space characters

Create the string t from the string s, removing all the spaces, newlines, tabulations, etc.

(defun remove-whitespace (s &aux |t|)
  "Return a copy of S (a sequence) excluding all the characters space, tab, linefeed, return, and formfeed."
  (setf |t|
    (remove-if
        (lambda (item) (find item '(#\Space #\Tab #\Linefeed #\Return #\Page)))
        s))
  |t|)

It would be better to simply return the result of REMOVE-IF, but the assignment requires the variable t. Note that T is a reserved constant in Lisp, so we use t (lowercase). The Lisp reader normally interns symbol names in uppercase, but enclosing the symbol name in vertical bars (pipes) forces the reader to intern the lowercase t. As the Lisp interpreter respects the case of symbol names, t is not the same name as T.
let t = s.replace(/\s/g,'');

This uses a regex.
\s means "a whitespace character"
g means "replace all occurrences"
#include <iostream>
#include <string>
#include <algorithm>
auto t = s;
t.erase(std::ranges::remove_if(t, [](const char c) { return std::isspace(c); }).begin(),t.end()) ;
New implementation...
< > ⌨
programming-idioms.org 
(defun remove-whitespace (s &aux |t|)
  "Return a copy of S (a sequence) excluding all the characters space, tab, linefeed, return, and formfeed."
  (setf |t|
    (remove-if
        (lambda (item) (find item '(#\Space #\Tab #\Linefeed #\Return #\Page)))
        s))
  |t|)
let t = s.replace(/\s/g,'');
auto t = s;
t.erase(std::ranges::remove_if(t, [](const char c) { return std::isspace(c); }).begin(),t.end()) ;
var t = new string(s.Where(c => !Char.IsWhiteSpace(c)).ToArray());
[Ch || Ch <- "This is a\tstring with\nwhite\rspaces", Ch /= 8, Ch /= 9, Ch /= 10, Ch /= 13, Ch /= 32 ].
t := strings.Map(func(r rune) rune {
	if unicode.IsSpace(r) {
		return -1
	}
	return r
}, s)
t = filter (not . isSpace) s
String t = s.replaceAll("\\s+", "");
String t = "";
for (char c : s.toCharArray())
    if (!isWhitespace(c)) t = t + c;
String t = "";
for (char c : s.toCharArray())
    switch (c) {
        case ' ', '\t', '\n', '\r' -> {}
        default -> t = t + c;
    }
String t = s.chars()
    .filter(c -> !isWhitespace(c))
    .mapToObj(c -> valueOf((char) c))
    .collect(joining());
  SetLength(t, Length(s));
  i := 0;
  for Ch in S do
    if (Ch > #32) then
    begin
      Inc(i);
      t[i] := Ch;
    end;
  SetLength(t, i);

t := ReplaceRegExpr('\s', s, '');
my $t = $s;
$t =~ s/\s*//g;

t = re.sub('\\s', '', s)
f = lambda x: x not in whitespace
t = ''.join(filter(f, s))
t = ''.join(s.split())
t = s.gsub(/[[:space:]]/, "")
t = s.gsub(/\s/, "")
let t: String = s.chars().filter(|c| !c.is_whitespace()).collect();