~ means NOT so *isempty* tells you if the vector is empty and *~isempty* tells you if the vector is _not_ empty.

Use the function to check if an array is empty: if isempty(u) % do something else % do something else end

Use isempty x = []; isempty(x) Then the answer is ans = logical 1

Is TEST a cell array? If so use {} to get at the contents (C-urly for C-ontents). The return value {[]} is not empty because it is a length one cell array - the contents of the cell array is an empty array.

For checking if an array is empty (that is, it doesn't contain any elements), you can use A.size == 0:

import numpy as np
In [2]: A = np.array([[1, 2], [3, 4]])

In [3]: A.size
Out[3]: 4

In [4]: B = np.array([[], []])

In [5]: B.size
Out[5]: 0

To check whether it only contains 0's you can check for np.count_nonzero(A):

In [13]: Y = np.array([[0, 0], [0, 0]])
In [14]: np.count_nonzero(Y)
Out[14]: 0

This can be done by using an AND statement in the "if" statement and making sure the "exist" check comes first. As long as the "exist" check is first, MATLAB will only continue on to the rest of the "if" statement ("isempty") if it is true. This way "isempty" will not error. if exist('x') && isempty(x) disp('Exists and empty!') end

Use CELLFUN

%# find empty cells
emptyCells = cellfun(@isempty,a);
%# remove empty cells
a(emptyCells) = [];

Note: a(i)==[] won't work. If you want to know whether the the i-th cell is empty, you have to use curly brackets to access the content of the cell. Also, ==[] evaluates to empty, instead of true/false, so you should use the command isempty instead. In short: a(i)==[] should be rewritten as isempty(a{i}).

if ~isempty(strfind(B, A)) condition 1 else condition 2 end The problem is that, even conceptually, this does not express what you actually want, so it's no wonder it does not work. You're not asking if A is found in B (in which case, using |isempty(strfind(...))| would work). You want to ask either (it's not clear from your question) if A is found in *all* of the Bs, or in *any* of the Bs. That's a completely different question, hence the syntax is different. |strfind| when given a cell array tells you, for each element of B, this is where I found A. Therefore, you have to ask |strfind|: for each element of B is the return value empty. And finally, you have to apply the or operator (depending on what you want) to that answer. So: if any(~cellfun(@isempty, strfind(B, A))) %possibly replace any by all condition1 else condition2 end

You can use the isempty() function in Matlab to accomplish your task: name = ''; % empty char variable if isempty(name) name = 'no name'; end This will get you the desired result.