Convert JSON to Table and Query Specific Value

I have the following JSON array:

{"views":[{"Name":"A","Conf":"High","View":"Negative"}, {"Name":"B","Conf":"Low","View":"Negative"}, {"Name":"C","Conf":"Low","View":"Negative"}]}

How can I convert it to Table? Also, how can I query a specific row of the table? (Example: Find value of "Conf" where Name is "C.)

So far I have:

jsonData = '{"views":[{"Name":"A","Conf":"High","View":"Negative"}, {"Name":"B","Conf":"Low","View":"Negative"}, {"Name":"C","Conf":"Low","View":"Negative"}]}'

structData = jsondecode(jsonData);

Answer 1

[Florian Bidaud]

jsonData = '{"views":[{"Name":"A","Conf":"High","View":"Negative"}, {"Name":"B","Conf":"Low","View":"Negative"}, {"Name":"C","Conf":"Low","View":"Negative"}]}'

jsonData = '{"views":[{"Name":"A","Conf":"High","View":"Negative"}, {"Name":"B","Conf":"Low","View":"Negative"}, {"Name":"C","Conf":"Low","View":"Negative"}]}'

structData = jsondecode(jsonData)

structData = struct with fields:
    views: [3×1 struct]

structDataTable = struct2table(structData.views)

structDataTable = 3×3 table
    Name       Conf          View    
    _____    ________    ____________

    {'A'}    {'High'}    {'Negative'}
    {'B'}    {'Low' }    {'Negative'}
    {'C'}    {'Low' }    {'Negative'}

structDataTable.Name

ans = 3×1 cell array
    {'A'}
    {'B'}
    {'C'}

structDataTable.Conf{[structDataTable.Name{:}]=='C'}

ans = 'Low'

[Monkey Coder]

Thanks Florian . Can you please also suggest how to query specific row in the table/struct? Example : Find value of "Conf" where Name is "C.

[Florian Bidaud]

structDataTable.Conf{[structDataTable.Name{:}]=='C'}

[Monkey Coder]

Thank you so much

[Monkey Coder]

Can I please check how to query data for a string value? It works with 'C' but throw an error when I try the following code:

structDataTable.Conf{[structDataTable.Name{:}]=='Cat'};

Error: Matrix dimensions must agree.

[Florian Bidaud]

Ah yes sorry, you need to use strcmp as follows :

structDataTable.Conf{strcmp([structDataTable.Name(:)],'Cat')};

[Monkey Coder]

Thanks, it works when there is a match. However, it throws an error when it cant find a match.

Error : Unable to perform assignment with 0 elements on the right-hand side.

How can I handle this?

[Florian Bidaud]

when you affect your value, first check if it's empty or not:

if ~isempty(structDataTable.Conf{strcmp([structDataTable.Name(:)],'Cat')})
    value = structDataTable.Conf{strcmp([structDataTable.Name(:)],'Cat')};
else
    value = nan;
end

[Monkey Coder]

sorry, I am getting "Unable to perform assignment with 0 elements on the right-hand side." on the following line.

if ~isempty(structDataTable.Conf{strcmp([structDataTable.Name(:)],'Cat')})