MATLAB: Index search in nested structure

find indexfor loopnested structstructure

Hi all,
I have a structure, which includes a nested structure.
It looks like this:
obj.characteristic1 = 'Test';
obj.characteristic2 = 'Test2';
obj.characteristic3 = 30;
obj.characteristic4 = struct('Name', [],...
                		'Age', [],...
                		'Height', [],...
                		'Gender', []);
The nested structure has 30 entries.
Target is to find a defined name, e.g. 'Tim'.
obj.characteristic4(1).name = 'Mike'
obj.characteristic4(2).name = 'Tim'
obj.characteristic4(3).name = 'David'
obj.characteristic4(4).name = 'Chris'
My solution on finding the index currently looks like this and is working.
fori=1:1:obj.characteristic3
                if strcmp(obj.characteristic4(i).name,'Tim')
                  nameIndex = i;
                end
            end
The question is, whether there is a smarter way without a for-loop to find the index of the name field with the matching string.
Thank you for your help.

Best Answer

In the case where the name might occur multiple times and you want to locate all of them, and you are only searching for one name:
idx = find(ismember({obj.characteristic4.name}, NameToSearchFor))
idx could be empty if the name is not found
In the case where the name occurs at most once or you only care about the first of them
[wasfound, idx] = ismember(NameToSearchFor, ismember({obj.characteristic4.name})
wasfound will be true if the name was found. idx will be the corresponding index in obj.characteristic4
In both cases you can extend NameToSearchFor to a cell array of character vectors of names to look for. With one order of the arguments to ismember, you are looking to see whether each name like 'Tim' matches somewhere in the characteristic4 list, and with the other order of arguments to ismember, you are looking to see whether the entries in the characteristic4 list match something in the list of names. Both have their uses.
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