how to identify empty , non-empty char matrix condition?

I have a matrix "A" with size 4x8 char and having values:

'01:04:00'

'01:03:00'

' '

'01:01:00'

I want to identify the index of empty char. I.e. 3rd one.

I tried,

% first one
A == ""
% second one
A == ''
% third one
isempty(A)
% forth one
isspace(A)
% fifth one
A == '        '
% sixth one
A == "        "
% everything shows zero output.

Can anyone please help?

Any help will be greatly appriciated.

Answer 1

[Stephen23]

M = [...
    '01:04:00'
    '01:03:00'
    '        '
    '01:01:00'];
strcmp('',cellstr(M)) % CELLSTR removes trailing whitespace characters.

ans = 4×1 logical array
   0
   0
   1
   0

cellfun(@isempty,cellstr(M)) % CELLSTR removes trailing whitespace characters.

ans = 4×1 logical array
   0
   0
   1
   0

all(M==32,2) % match space character only.

ans = 4×1 logical array
   0
   0
   1
   0

all(M==' ',2) % match space character only.

ans = 4×1 logical array
   0
   0
   1
   0

all(isstrprop(M,'wspace'),2) % match any whitespace character.

ans = 4×1 logical array
   0
   0
   1
   0

[MP]

Really!!

Indeed that made a great help!

Thank you very much.

Answer 2

[MP]

@Stephen23: Could you please also look into my another question?

https://in.mathworks.com/matlabcentral/answers/1762535-how-to-find-the-nearest-matrix-between-two-matrices?s_tid=srchtitle