_wp_json_convert_string( string $input_string ): string

4471function _wp_json_convert_string( $input_string ) {4472	static $use_mb = null;4473	if ( is_null( $use_mb ) ) {4474		$use_mb = function_exists( 'mb_convert_encoding' );4475	}4476 4477	if ( $use_mb ) {4478		$encoding = mb_detect_encoding( $input_string, mb_detect_order(), true );4479		if ( $encoding ) {4480			return mb_convert_encoding( $input_string, 'UTF-8', $encoding );4481		} else {4482			return mb_convert_encoding( $input_string, 'UTF-8', 'UTF-8' );4483		}4484	} else {4485		return wp_check_invalid_utf8( $input_string, true );4486	}4487}