Clear Properties in App Designer

I have a Property in my App Designer defined as ''Index''.

This Property is used in most of my callback functions to access specific values.

However, before start to run any callback function, I need to ''clear'' the value of this Property so that I do not have influence of previous values in the callback I'm current running.

I tried to use

clearvars app.Index

but did not have the expected result.

Any ideas?

Answer 1

[Adam Danz]

> I need to ''clear'' the value of this Property so that I do not have influence of previous values in the callback I'm current running

You can clear the content of that property using

app.Index = []; % numeric data
app.Index = {}; % cell arrays
app.Index = ''; % character arrays
app.Index = ""; % strings
% etc...

That can be used as a flag to ignore a section of code,

if ~isempty(app.Index)
    % stuff
end

Addendum

To create an empty table

app.Index = table(); 

To clear a table and maintain the headers

app.Index(:,:) = [];  % Preserves the class of each column 
% or
app.Index = table([],[],{}); % Creates a new 0x3 table and defines classes for each column

[THULYO NEDER]

Thanks for your reply Adam.

In case I have a table assigned for this property, which is the most recommended to use?

[Adam Danz]

If you wanted to replace it with an empty table,

app.Index = table(); 

If you want to clear the data and maintain the headers,

app.Index = array2table(ones(0,width(app.Index)),'VariableNames', app.Index.Properties.VariableNames);

Both options will pass the isempty test.

[THULYO NEDER]

Thanks Adam.

It worked!

[Adam Danz]

Thanks for the feedback, @THULYO NEDER

I've updated the answer to provide a better method of clearing a table,

app.Index(:,:) = []; 

This method preserves the class of each column.