wp_specialchars_decode() WordPress Function

function wp_specialchars_decode( $string, $quote_style = ENT_NOQUOTES ) {
	$string = (string) $string;

	if ( 0 === strlen( $string ) ) {
		return '';
	}

	// Don't bother if there are no entities - saves a lot of processing.
	if ( strpos( $string, '&' ) === false ) {
		return $string;
	}

	// Match the previous behaviour of _wp_specialchars() when the $quote_style is not an accepted value.
	if ( empty( $quote_style ) ) {
		$quote_style = ENT_NOQUOTES;
	} elseif ( ! in_array( $quote_style, array( 0, 2, 3, 'single', 'double' ), true ) ) {
		$quote_style = ENT_QUOTES;
	}

	// More complete than get_html_translation_table( HTML_SPECIALCHARS ).
	$single      = array(
		''' => '\'',
		''' => '\'',
	);
	$single_preg = array(
		'/&#0*39;/'   => ''',
		'/&#x0*27;/i' => ''',
	);
	$double      = array(
		'"' => '"',
		'"' => '"',
		'"' => '"',
	);
	$double_preg = array(
		'/&#0*34;/'   => '"',
		'/&#x0*22;/i' => '"',
	);
	$others      = array(
		'&lt;'   => '<',
		'&#060;' => '<',
		'&gt;'   => '>',
		'&#062;' => '>',
		'&amp;'  => '&',
		'&#038;' => '&',
		'&#x26;' => '&',
	);
	$others_preg = array(
		'/&#0*60;/'   => '&#060;',
		'/&#0*62;/'   => '&#062;',
		'/&#0*38;/'   => '&#038;',
		'/&#x0*26;/i' => '&#x26;',
	);

	if ( ENT_QUOTES === $quote_style ) {
		$translation      = array_merge( $single, $double, $others );
		$translation_preg = array_merge( $single_preg, $double_preg, $others_preg );
	} elseif ( ENT_COMPAT === $quote_style || 'double' === $quote_style ) {
		$translation      = array_merge( $double, $others );
		$translation_preg = array_merge( $double_preg, $others_preg );
	} elseif ( 'single' === $quote_style ) {
		$translation      = array_merge( $single, $others );
		$translation_preg = array_merge( $single_preg, $others_preg );
	} elseif ( ENT_NOQUOTES === $quote_style ) {
		$translation      = $others;
		$translation_preg = $others_preg;
	}

	// Remove zero padding on numeric entities.
	$string = preg_replace( array_keys( $translation_preg ), array_values( $translation_preg ), $string );

	// Replace characters according to translation table.
	return strtr( $string, $translation );
}