PHP regex whitespace shorthand \s can be used to match whitespace characters. These are the characters it will match.
| Char | Dec val | Oct val |
|---|---|---|
| tab | 9 | \011 |
| newline | 10 | \012 |
| form feed | 12 | \014 |
| carriage return | 13 | \015 |
| space | 32 | \040 |
This is convenient way to remove whitespace or replace multiple whitespaces to single space. Here are some preg_replace examples using whitespace.
preg_replace – remove all whitespaces
<?php
$str = "foo bar\nfoo";
$newstr = preg_replace('/\s/', "", $str, -1, $count);
if ($count > 0) {
echo "newstr after $count replacement(s):\n$newstr\n";
} else {
echo "No replacement\n";
}
?>newstr after 2 replacement(s): foobarfoo
Env: PHP version 7.4.33 (Linux)
preg_replace – collapse multiple whitespaces to single space
<?php
$str = "foo bar\n\n\nfoo\nbar";
$newstr = preg_replace('/\s+/', ' ', $str, -1, $count);
if ($count > 0) {
echo "newstr after $count replacement(s):\n$newstr\n";
} else {
echo "No replacement\n";
}
?>newstr after 3 replacement(s): foo bar foo bar
Env: PHP version 7.4.33 (Linux)
