在单元格数组（Matlab）中查找字符串的行索引

Question

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] 

Answer 1

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 .

Answer 2

YOu can use strfind to get the indices which has string name and then use logical indices to get 23 out of the obtained indices.

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

% find indices of name
idx = strfind(C(:,1), 'name');
idx = find(not(cellfun('isempty', idx)));
% pick 23 from 3rc column

iwant =idx((str2double(C(idx,3))==23))