How to do an 'if loop' that finds if a column vector contains a string

To put it in words, how would you do

if y(:,i) contains ('A' and 'B') or ('C' and 'D')

[Jan]

There are no "if-loops" in any programming language. if is simply not a loop.

Answer 1

[Jan]

A bold guess:

if all(ismember('AB', y(:,i))) || all(ismember('CD', y(:, i)))

Answer 2

[Geoff Hayes]

Joey - consider using strfind or regexp. If the former, then you could try

 str = y(:,k)';  % ensure that the string is a row

 if (~isempty(strfind(str,'A')) && ~isempty(strfind(str,'B'))) || ...
    (~isempty(strfind(str,'C')) && ~isempty(strfind(str,'D')))

     % do something
 end

Note how k is used instead of i (which MATLAB uses as a representation of the imaginary number). We first need to convert the string to a row of characters so that we can use strfind to search for what we are looking for. If the result returned from this call is empty, then we know that the characters don't appear in the string. That's why we use the ~isempty(...).

If you wish to use regexp, then you could try something similar

 str = y(:,k)';

 if (~isempty(regexp(str,'[A]')) && ~isempty(regexp(str,'[B]'))) || ...
    (~isempty(regexp(str,'[C]')) && ~isempty(regexp(str,'[D]')))

     % do something
 end

(There may be a better way to make use of regexp so that the above code is simplified.)

[Joey]

nothing seems to be working so far. What I have is a 5x10000 matrix y that is supposed to represent 5 card poker hands. The first character is the card and the second character is the suit. It looks like

AH  QS  ...
4C  3C  ...
3D  AD  ...
2S  5D  ...
TD  AS  ...

What I want to do is find how many hands have a straight in them, so I need to search each column for an A,2,3,4,5 or 2,3,4,5,6, or 3,4,5,6,7 and so on.

[Geoff Hayes]

Joey - given your example, it would appear that your input array is a cell array. Is this the case? Because that would mean that the code would have to be modified to handle that. For example,

data = {'AH'  'QS'
        '4C'  '3C'
        '3D'  'AD'
        '2S'  '5D' 
        'TD'  'AS' };

 cards = char(data(:,1));
 value = cards(:,1)';
 suit  = cards(:,2)';
 if (~isempty(strfind(str,'A')) && ~isempty(strfind(suit,'H')))
     fprintf('you have the ace of hearts!\n');
 end