MATLAB: How to access a field in a structure array using a cell array containing strings corresponding to these fields using a for cycle

Question

I would like to access different fields of a structure array using a for cycle, so I created a cell array containing the same strings used to indexing the structure array but I am returned errors because the format to access a structure array needs a string after the point. As an example, if I have a structure array named A, and the cell array indicating the fields of the structure array is B, I would like to do the subsequent thing:

B={'first','second','third','fourth','fifth'};
for i=1:length(b)
   A.B(i)=A.B(i)+1
end

to avoid doing the following thing manually:

A.first=A.first+1;
A.second=A.second+1;
A.third=A.third+1;
A.fourth=A.fourth+1;
A.fifth=A.fifth+1;

but in the for cycle Matlab is searching for the string B, that obviously doesn't exist. I would use such a for cycle to avoid to manually enter every single string. Does anybody know how to do that? Thanks for helping.

Answer 1

You almost had the syntax correct. Use "dynamic field names" by enclosing the field name variable (in this case B{i}) inside parentheses:

B={'first','second','third','fourth','fifth'};
for i=1:length(B)
   A.(B{i}) = A.(B{i})+1;
end