Adding a new field to a struct array

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Hey All! I'm trying to add a new field to a struct array inline. I have the following struct:
A(1).name = 'bob';
A(2).name = 'cindy';
newstruct = 'address'
How do I go about adding the a field A.address to the array struct with the field name being define din the newstruct variable? The existing array should then look like the following:
A(1).name = 'bob';
A(2).name = 'cindy';
A(1).address = [];
A(2).address = [];

Accepted Answer

Walter Roberson
Walter Roberson on 27 Jan 2018
A(1).(newstruct) = value;
If you have a cell array of contents to be put into existing entries, then you can use
[A.(newstruct)] = values_cell{:};
to set all of them at the same time.
  2 Comments
sarah wentzel
sarah wentzel on 23 Jan 2022
what are value in the first option and values_cell in the second? are those new variables?
Walter Roberson
Walter Roberson on 11 Jun 2022
value in the above could be any variable or expression of any size or data type.
values_cell in the above would have to be a variable containing a cell array, in which the number of entries was the same as numel(A); each cell entry could be any data type or size.
More obscurely, values_cell could instead be the name of a true function (not function handle) for a function that could be called with no parameters, and which returned a cell array.
More obscurely still, values_cell could be the name of a class with a class constructor that could be invoked with no parameters, and the class defined subsref with {} operation, or defined the specialized method for overloading {}, so that the class name with no parameters defines an object and the {:} invoked whatever the {} operation was redefined as.

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More Answers (2)

Kallam Haranadha Reddy
Kallam Haranadha Reddy on 27 Jan 2018
A(1).name = 'bob';
A(2).name = 'cindy';
A(1).address = ' Flat No.502, Apple Towers,...
 1st line, Ravindra Nagar, Guntur,Andhra Pradesh, India,PIN-522006';
A(2).address = ' Flat No.102, Balaji Towers,...
2nd line, Brodipet, Guntur, Andhra Pradesh, India, PIN-522006';

sarah wentzel
sarah wentzel on 23 Jan 2022
Edited: sarah wentzel on 23 Jan 2022
I created this cell
somecell = struct('Name', {'bob', 'lea', 'pat'}, 'Birth_year', {1990, 1988, 2021})
and now I want to add new information, favorite color. I know I can do it one by one like this:
somecell(1).color = 'blue'
somecell(2).color = 'red'
somecell(3).color = 'green'
But is there a way to do it with only one line? something like;
somecell (:,3).color = {'blue', 'red', 'green'}
thank you!
  1 Comment
Stephen23
Stephen23 on 23 Jan 2022
Edited: Stephen23 on 23 Jan 2022
S = struct('Name', {'bob', 'lea', 'pat'}, 'Birth_year', {1990, 1988, 2021})
S = 1×3 struct array with fields:
Name Birth_year
[S.color] = deal('blue','red','green')
S = 1×3 struct array with fields:
Name Birth_year color
Or from a cell array:
C = {'small', 'large', 'medium'};
[S.tshirtsize] = C{:}
S = 1×3 struct array with fields:
Name Birth_year color tshirtsize

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