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arraysstringmatlabcell-array

Find row Index of strings in cell Array (Matlab)

If I have a cell array C:

C =  {'name'  'hh' '23' []     []
    'last'  'bb' '12' '8'    'hello'
    'In'    'kk' '12' '2131' []
    'name'  'kk' '23' []     []
    'name'  'cv' '22' []     []
    'name'  'ph' '23' []     [] } ;

How can I get the row index of all the rows that have 'name' in the first column and '23' in the third column?

indexresult = [1,4,6]
Solution

  • The simplest way to do this (all-versions compatible) would be to just use strcmp, which can accept cell arrays and does a "string compare".

    One liner

    indexresult = find(strcmp(C(:,1), 'name') & strcmp(C(:,3), '23'));
% indexresult = [1; 4; 6];

    Explanation

    % Get logical array of rows where first column is 'name'
logicalname = strcmp(C(:,1), 'name');
% Get logical array of rows where third column is '23'
logical23 = strcmp(C(:,3), '23');
% Get logical array where both of the above are true, using and (&)
logicalname23 = strcmp(C(:,1), 'name') & strcmp(C(:,3), '23');
% Get indices from logical array using find
indexresult = find(strcmp(C(:,1), 'name') & strcmp(C(:,3), '23'));
% If you wanted a row vector instead of column vector, just transpose too
indexresult = find(strcmp(C(:,1), 'name') & strcmp(C(:,3), '23')).';

    If you want to be case insensitive (matching 'name', 'NAME', 'Name', ...) then use strcmpi instead of strcmp.