valid_unicode() │ WP 2.7.0

Determines if a Unicode codepoint is valid.

The definition of a valid Unicode codepoint is taken from the XML definition:

Characters > > … > Legal characters are tab, carriage return, line feed, and the legal characters of > Unicode and ISO/IEC 10646. > … > Char ::= #x9 | #xA | #xD | [#x20-#xD7FF] | [#xE000-#xFFFD] | [#x10000-#x10FFFF]

No Hooks.

Returns

true|false. Whether or not the codepoint is a valid Unicode codepoint.

Usage

valid_unicode( $i );

$i(int) (required)

Unicode codepoint.

Notes

• See: https://www.w3.org/TR/xml/#charsets

Changelog

valid_unicode() valid unicode code ^{WP 6.9.1}

function valid_unicode( $i ) {
	$i = (int) $i;

	return (
		0x9 === $i || // U+0009 HORIZONTAL TABULATION (HT)
		0xA === $i || // U+000A LINE FEED (LF)
		0xD === $i || // U+000D CARRIAGE RETURN (CR)
		/*
		 * The valid Unicode characters according to the XML specification:
		 *
		 * > any Unicode character, excluding the surrogate blocks, FFFE, and FFFF.
		 */
		( 0x20 <= $i && $i <= 0xD7FF ) ||
		( 0xE000 <= $i && $i <= 0xFFFD ) ||
		( 0x10000 <= $i && $i <= 0x10FFFF )
	);
}