conditional logic inside conditional logic

Hello, I would like to know if there is any way to write the following in one line ?

if isfield(hund.A)
    if hund.A == 1
        'do something'
    end
end

Since I need to know if field 'A' exist I cannot just do if hund.A == 1 right away.

Is there a way to do something like this:

if isfield(hund.A) Then if hund.A == 1
   'do something'
end

I would like to avoid too many if's. Thanks in advance...

Answer 1

[Jan]

if isfield(hund.A)

This will not work. I guess you mean:

if isfield(hund, 'A')

Then this works:

if isfield(hund, 'A') && hund.A == 1

The condition hund.A==1 is evaluated only, if the first condition is true. If the field 'A' does not exist, the 2nd part is not reached. This is called "shortcircuting".

Alternative: Create a function, which replies a default value for not existing fields:

function R = SafeGetField(S, F)
if isfield(S, F)
    R = S.F;
else
    R = [];
end
end

Then:

if isequal(SafeGetField(hund, 'A'), 1)

Or:

function T = CompareField(S, F, V)
if isfield(S, F)
    T = isequal(S.F, V);
else
    T = false;
end
end

and in the main code:

if CompareField(hund, 'A', 1)

[Martin]

I meant as you said

if isfield(hund, 'A') 

ya. Great, thanks for answer, didnt even knew that concept of "shortcircuting"