mu_dropdown_languages() WordPress Function

function mu_dropdown_languages( $lang_files = array(), $current = '' ) {
	$flag   = false;
	$output = array();

	foreach ( (array) $lang_files as $val ) {
		$code_lang = basename( $val, '.mo' );

		if ( 'en_US' === $code_lang ) { // American English.
			$flag          = true;
			$ae            = __( 'American English' );
			$output[ $ae ] = '<option value="' . esc_attr( $code_lang ) . '"' . selected( $current, $code_lang, false ) . '> ' . $ae . '</option>';
		} elseif ( 'en_GB' === $code_lang ) { // British English.
			$flag          = true;
			$be            = __( 'British English' );
			$output[ $be ] = '<option value="' . esc_attr( $code_lang ) . '"' . selected( $current, $code_lang, false ) . '> ' . $be . '</option>';
		} else {
			$translated            = format_code_lang( $code_lang );
			$output[ $translated ] = '<option value="' . esc_attr( $code_lang ) . '"' . selected( $current, $code_lang, false ) . '> ' . esc_html( $translated ) . '</option>';
		}
	}

	if ( false === $flag ) { // WordPress English.
		$output[] = '<option value=""' . selected( $current, '', false ) . '>' . __( 'English' ) . '</option>';
	}

	// Order by name.
	uksort( $output, 'strnatcasecmp' );

	/**
	 * Filters the languages available in the dropdown.
	 *
	 * @since MU (3.0.0)
	 *
	 * @param string[] $output     Array of HTML output for the dropdown.
	 * @param string[] $lang_files Array of available language files.
	 * @param string   $current    The current language code.
	 */
	$output = apply_filters( 'mu_dropdown_languages', $output, $lang_files, $current );

	echo implode( "\n\t", $output );
}