wp_is_valid_utf8() │ WP 6.9.0

Determines if a given byte string represents a valid UTF-8 encoding.

Note that it’s unlikely for non-UTF-8 data to validate as UTF-8, but it is still possible. Many texts are simultaneously valid UTF-8, valid US-ASCII, and valid ISO-8859-1 (latin1).

Example:

true === wp_is_valid_utf8( '' );
true === wp_is_valid_utf8( 'just a test' );
true === wp_is_valid_utf8( "\xE2\x9C\x8F" );    // Pencil, U+270F.
true === wp_is_valid_utf8( "\u{270F}" );        // Pencil, U+270F.
true === wp_is_valid_utf8( '✏' );              // Pencil, U+270F.

false === wp_is_valid_utf8( "just \xC0 test" ); // Invalid bytes.
false === wp_is_valid_utf8( "\xE2\x9C" );       // Invalid/incomplete sequences.
false === wp_is_valid_utf8( "\xC1\xBF" );       // Overlong sequences.
false === wp_is_valid_utf8( "\xED\xB0\x80" );   // Surrogate halves.
false === wp_is_valid_utf8( "B\xFCch" );        // ISO-8859-1 high-bytes.
												// E.g. The “ü” in ISO-8859-1 is a single byte 0xFC,
												// but in UTF-8 is the two-byte sequence 0xC3 0xBC.

A “valid” string consists of “well-formed UTF-8 code unit sequence[s],” meaning that the bytes conform to the UTF-8 encoding scheme, all characters use the minimal byte sequence required by UTF-8, and that no sequence encodes a UTF-16 surrogate code point or any character above the representable range.

No Hooks.

Returns

true|false. Whether the provided bytes can decode as valid UTF-8.

Usage

wp_is_valid_utf8( $bytes ): bool;

$bytes(string) (required)

String which might contain text encoded as UTF-8.

Notes

• See: https://www.unicode.org/versions/Unicode16.0.0/core-spec/chapter-3/#G32860

Changelog

wp_is_valid_utf8() wp is valid utf8 code ^{WP 7.0}

function wp_is_valid_utf8( string $bytes ): bool {
	return mb_check_encoding( $bytes, 'UTF-8' );
}
else :
/**
 * Fallback function for validating UTF-8.
 *
 * @ignore
 * @private
 *
 * @since 6.9.0
 */
function wp_is_valid_utf8( string $string ): bool {
	return _wp_is_valid_utf8_fallback( $string );
}