How to replace multiple and whitespace with one and shrink whitespace only chunks to a space?

Question

I have the following custom text and HTML:

$text = "<p>Hello World!&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;Javascript development&nbsp;PHP Developer&nbsp;</p>";

How can I change that text, using regular expressions, into the following:

"<p>Hello World!&nbsp;Javascript development&nbsp;PHP Developer</p>"

Code:

$text = "<p>Hello World!&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;Javascript development&nbsp;PHP Developer&nbsp;</p>";
$result = preg_replace("/(&nbsp;)+/", "&nbsp;", $text);
echo $result;

What have you tried? Include your code (in the question, not as a link!). What problems did you encounter? — Jonathan Hall, Apr 02 '19 at 10:26
Try `preg_replace(["/\s* (?:\s* )*\s*/", "/\s+/"], [' ',' '], $text);` ([demo](https://3v4l.org/X5cRA)) — Wiktor Stribiżew, Apr 02 '19 at 10:28
@WiktorStribiżew Your regexp partially works. How to add such a rule that at the beginning and at the end of the text there was no `&nbsp` ? — Andreas Hunter, Apr 02 '19 at 10:33
`preg_replace(['/^((?: |\s)+)|(?1)$/', '/\s* (?:\s* )*\s*/', '/\s+/'], ['', ' ',' '], trim($text));`, see https://3v4l.org/U4faU — Wiktor Stribiżew, Apr 02 '19 at 10:36
@AndreasHunter [Posted](https://stackoverflow.com/a/55472840/3832970) as an answer. — Wiktor Stribiżew, Apr 02 '19 at 10:44
https://stackoverflow.com/a/42602323/10230696 has nothing to do with the current question since it is not about shrinking multiple consecutive single word to one occurrence. — Wiktor Stribiżew, Apr 03 '19 at 07:42

cfillion · Answer 1 · 2019-04-02T10:33:07.880

2

Your input text contains spaces after most   which your regex does not account for. You can use \s* to allow for zero or more spaces before and after each non-breakable space HTML entity.

$result = preg_replace('/(\s*&nbsp;\s*)+/', '&nbsp;', $text);

edited Apr 02 '19 at 10:33

answered Apr 02 '19 at 10:28

cfillion

1,340
11
16

score 2 · Accepted Answer · answered Apr 02 '19 at 10:44

You may use

$find = ['/^((?:&nbsp;|\s)+)|(?1)$/', '/\s*&nbsp;(?:\s*&nbsp;)*\s*/', '/\s+/'];
$replace = ['', '&nbsp;',' '];
$text = preg_replace($find, $replace, trim($text));

See the PHP demo.

Details

'/^((?: |\s)+)|(?1)$/' => '' removes   and whitespaces at the start/end of string ((?1) here just recurses (?: |\s)+ and is here to make the pattern a bit shorter)
'/\s* (?:\s* )*\s*/' => ' ' replaces all sequences of whitespace and   with at least one   with one  
'/\s+/' => ' ' replaces 1+ whitespaces with 1 regular space.

How to replace multiple and whitespace with one and shrink whitespace only chunks to a space?

2 Answers2