Regular Expression for Space Character Check

/[^\s　]/

Blank letters(\s) and double-byte spaces ( ) other than(^) are included.

– \s is a blank character abbreviation, including single-byte spaces, tabs, and new-line characters.
– The space after \s is full-width space
– Double-byte spaces are treated the same as Kanji, so the are not included in \s.
– Brackets([]) mean one character in parentheses. If there is no [], it will search for chunks of “\s”. If you use ^ outside of [], it means a different meaning.

$value = "富士山　が良く見える";

if (preg_match('/[^\s　]+$/u', $value)){
	echo "スペースが含まれています";
} else {
	echo "スペースが含まれていません";
}

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