Syntax Issue in If Statement Using Handles

I am trying to write an if statement in a function, to determine if the handles values are of valid type, as per the stipulation in the texts written above said handles in the GUI.

For handle 'edit1' I have written:

if handles.edit1 == NaN 

set(handles.edtit2, 'enable', 'off') && set(handles.listbox1, 'string', 'Date must be of stated syntax')

else set(handles.edit2, 'enable', 'on')

end

During runtime the code skips to else not flagging

if handles.edit1 == Nan

as true thus setting the 'handles.edit2' off and having the error showing in listbox1.

What is wrong with my if statement?

Answer 1

[Stephen23]

You cannot test for equality of NaN's, because as the documentation clearly states, NaN's are not equal to each other. Use isnan instead:

>> handles.edit1 = NaN;
>> handles.edit1 == NaN
ans =
     0
>> isnan(handles.edit1)
ans =
     1

Answer 2

[Walter Roberson]

Use ishghandle() instead testing for NaN .

[Jay]

Thanks Walter,

I will see if that does what I need.