function [validNames, modified] = makeValidName(names, modException)

            %MAKEVALIDNAME Construct valid MATLAB identifiers from input names

            %   MAKEVALIDNAME is a private function for table that wraps

            %   around MATLAB.LANG.MAKEVALIDNAME. It adds exception control

            %   for when input names contains invalid identifier.

            %

            %   MODEXCEPTION controls warning or error response when NAMES

            %   contains invalid MATLAB identifiers. Valid values for

            %   MODEXCEPTION are 'error', 'warnSavedLong', 'warn', 'warnSaved',

            %   'silent', and 'error'. 'error' and 'warnSavedLong' are for names that

            %   do not need to be valid MATLAB identifiers, but still must follow some

            %   rules. 'warn', 'warnSaved', and 'silent' are for patching up names to

            %   valid MATLAB identifiers and exist for backward compatibility.

            import matlab.internal.datatypes.warningWithoutTrace;

            import matlab.internal.tabular.private.varNamesDim.checkReservedNames;

            import matlab.internal.tabular.validateVariableNameLength;

            if strcmp(modException,'error') 

                % For variable names that no longer need to be valid MATLAB identifiers,

                % check length and conflicts with reserved names.

                validNames = names; % return the originals, or possibly error 

                if ischar(names), names = { names }; end % unusual case, not optimized 

                % error if empty, too long, or reserved.

                validateVariableNameLength(names,'MATLAB:table:VariableNameLengthMax'); 

                checkReservedNames(names); 

                modified = false(size(names)); 

            elseif strcmp(modException, 'warnLength')

                % For variable names that no longer need to be valid MATLAB identifiers,

                % check length and conflicts with reserved names. If a tabular method is

                % making a name, warn rather than erroring if the name is too long or

                % conflicts with a reserved name.

                validNames = names; % return the originals, or possibly error

                if ischar(names), names = { names }; end % unusual case, not optimized

                tooLong = validateVariableNameLength(names,'MATLAB:table:VariableNameLengthMax');

                conflicts = checkReservedNames(names);

                modified = tooLong | conflicts;

                if any(modified)

                    % Unlike in the 'warn' case below that calls makeValidName, here

                    % makeUniqueStrings fixes both names that are too long and names that

                    % conflict with reservedNames.

                    validNames(modified) = matlab.lang.makeUniqueStrings(validNames(modified),validNames,namelengthmax);

                    if any(conflicts)

                        reservedNameConflicts = names(conflicts);

                        warningWithoutTrace(message('MATLAB:table:ModifiedVarnamesReservedConflict',reservedNameConflicts{1}));

                    end

                    if any(tooLong)

                        warningWithoutTrace(message('MATLAB:table:ModifiedVarnamesLengthMax'));

                    end

                end

            elseif strcmp(modException, 'warnSaved') || strcmp(modException, 'resolveConflict')

                % For variable names that no longer need to be valid MATLAB identifiers,

                % check length and conflicts with reserved names. Warn if any need to be

                % patched up because of length or conflicts.

                if strcmp(modException, 'resolveConflict')

                    % handle the case when the names contain empty char ''

                    emptyNames = matches(names,'');

                    names(emptyNames) = {'x'}; 

                end

                validNames = names; % return the originals, or possibly error

                if ischar(names), names = { names }; end % unusual case, not optimized

                tooLong = validateVariableNameLength(names,'MATLAB:table:VariableNameLengthMax');

                conflicts = checkReservedNames(names);

                modified = tooLong | conflicts;

                if any(modified)

                    % Unlike in the 'warn' case below that calls makeValidName, here

                    % makeUniqueStrings fixes both names that are too long and names that

                    % conflict with reservedNames.

                    validNames(modified) = matlab.lang.makeUniqueStrings(validNames(modified),validNames,namelengthmax);

                    if strcmp(modException, 'warnSaved')

                        if any(conflicts)

                            reservedNameConflicts = names(conflicts);

                            warningWithoutTrace(message('MATLAB:table:ModifiedAndSavedVarnamesReserved',reservedNameConflicts{1}));

                        end

                        if any(tooLong)

                            warningWithoutTrace(message('MATLAB:table:ModifiedAndSavedVarnamesLengthMax'));

                        end

                    end

                end

            else % 'warn', 'warnSavedLegacy', 'silent'

                [validNames, modified] = matlab.lang.makeValidName(names);

                conflicted = checkReservedNames(validNames);

                if any(conflicted)

                    validNames(conflicted) = matlab.lang.makeUniqueStrings(validNames(conflicted),validNames,namelengthmax);

                end

                modified = modified | conflicted;

                if any(modified)

                    switch modException % error or warn per level specified

                        case 'warn'

                            warningWithoutTrace(message('MATLAB:table:ModifiedVarnames'));

                        case 'warnSavedLegacy'

                            warningWithoutTrace(message('MATLAB:table:ModifiedAndSavedVarnames'));

                        case 'warnUnstack'

                            warningWithoutTrace(message('MATLAB:table:ModifiedVarnamesUnstack'));

                        case 'warnRows2Vars'

                            warningWithoutTrace(message('MATLAB:table:ModifiedVarnamesRows2Vars'));

                        case 'silent'

                            % Used by summary and other functions where we would like to convert to

                            % valid MATLAB identifiers without displaying any warning

                        otherwise

                            assert(false);

                    end

                end

            end 

        end