find fields in Matlab structures

Question

say I have a large structure with lots of names (eg 'a', 'b', etc). Given a name and without knowing the index of that particular name, I would like to find that name, similar to the find() command so that I can write additional fields to it

dat.name = 'a'
dat(2).name = 'b'
...
dat(26).name = 'z'

dat.name == 'a'

% MATLAB error
Error using  == 
Too many input arguments. 

Answer 1

If I undersand corretly, you want to find an index/indexes in struct array for which name field has given value? If yes, you can do as follows:

indexes = find(strcmp({dat(:).name}, 'a'))

Answer 2

To get the list of fields in a struct (as a cell array of strings), use:

fields(myStruct)

To access the value of a field where the name of the field is held in a variable (as a string), use:

myStruct.(fieldName)

Answer 3

If all your strings are one-character, you can use

>> find([dat.name] == 'b') %// concat into a single string (character vector)

ans =

     2

If the strings may have any number of characters:

>> [temp{1:numel(dat)}] = deal(dat.name);  %// build a cell array of strings
>> find(strcmp(temp,'b'))

ans =

     2