Help with return to nested loop

Question

Maya Harel 2020-5-6

0
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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/523330-help-with-return-to-nested-loop

评论： Image Analyst 2020-5-8

Hi, I need help with loops,

I have a while loop and in it I need to check input so I used nestef if

if the input is not valid it will print a msg and what I cannot seem to do is to send it beck to the beginning of the while loop to insert a different input

But whenever I try to print break or return at the end of the if, it just ends the whole function and not returns to the beggining of the loop

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KSSV 2020-5-6

Show us the whole code ..

Maya Harel 2020-5-6

在 MATLAB Online 中打开

function spellMat = SpellStoring()
    %the function will recive spells, check their validity and if they are
    %valid, and if so it will add them to a metrix
i = 0;
x = 1;
while x==1 %will continue forever until an inside break
i = i+1; %row number
    spell = input("Please enter a spell. to stop enter the word 'stop'",'s');
    grade = str2double(spell(5:7)); %transfer the 5-7 varieble to one grade
    if strcmp(spell,'stop') %check if writen stop
        return
    else %if not, continue to check validity
        if isempty(intersect('HP RW HG',spell(1:2)))... %compare name to valid ones
            || isempty(intersect('ABCDEFG',spell(3)))... %compare grade to valid ones
            || isempty(intersect('IAC',spell(4)))... %compare spell to valid ones
            || grade <=100 && grade<= 000 || isempty(intersect('WSCN',spell(8))) 
                %check grade and tresure validity
                disp('Invalid spell representation');
                return
        end
    end
spellMat = zeros(i,8);
spellMat = [spell; spellMat];
end
end

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Answer 1

Julian Schmid 2020-5-6

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https://ww2.mathworks.cn/matlabcentral/answers/523330-help-with-return-to-nested-loop#answer_430608

编辑：Julian Schmid 2020-5-6

在 MATLAB Online 中打开

From what I got you want to do something like that? It is easier to get an idea, if you provide the code you have written so far. The break or return statement does not end the if statement but the loop you are currently in.

inputArray = logical([1 0 1 0 0]); % can be strings and other numbers
nInput = length(inputArray);
ii = 1; % initialize index counter
while ii ~= nInput % nInput = number of arguments you want to check
    if  inputArray(ii) == false % or strcmp(inputArray(ii),'some condition') or ...
        % input is wrong, display a message
        disp('Something went wrong')
    end
    
    % increase counter
    ii = ii + 1;
end

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Julian Schmid 2020-5-6

编辑：Julian Schmid 2020-5-6

在 MATLAB Online 中打开

Ok, so maybe this is something you can work from. It is not ideal, because it does not preallocate spellArray but as long as there are not too many inputs provided by the user you should be fine.

Also instead of using isempty(intersect(...)) you should use the contains function e.g. contains(spell(1:2),{'HP RW HG'}). You dont catch inputs like RABC100W with the intersect function as it returns 'R' and not an empty output

function spellArray = SpellStoring()
    % the function will recive spells, check their validity and if they are
    % valid, and if so it will add them to a matrix
    spellArray = [];
    while 1 % will continue forever until an inside break
        spell = input("Please enter a spell. to stop enter the word 'stop':",'s');
        if strcmp(spell,'stop') % check if writen stop
            % use break to exit the while loop
            % use return to the function which called this function (parent function)
            % the input provided by the user is returned in spellArray variable
            break
        elseif numel(spell) < 8
            % check here to make sure the input has at least 8 characters
            % otherwise we get an error when validating the parts of the
            % input
            
            % check grade and tresure validity
            disp('Invalid spell representation');
        else % if not, continue to check validity
            grade = str2double(spell(5:7)); % transfer the 5-7 varieble to one grade
            if ~contains(spell(1:2),{'HP','RW','HG'}) ... %compare name to valid ones
                    || isempty(intersect('ABCDEFG',spell(3)))... %compare grade to valid ones
                    || isempty(intersect('IAC',spell(4)))... %compare spell to valid ones
                    || contains(spell(5:7),'000') ...
                    || grade >= 100 ...
                    || isempty(intersect('WSCN',spell(8)))
                
                % check grade and tresure validity
                disp('Invalid spell representation');
            else % spell is valid so add it to the array
                spellArray = [spell;spellArray];
            end
        end
    end
end

Maya Harel 2020-5-6

编辑：Image Analyst 2020-5-8

Thank you so much. It works!

Image Analyst 2020-5-8

Maya can you then "Accept this answer" to give Julian credit (reputation points) for helping you? And also to let others know it's solved and ou've moved on. Thanks in advance.

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