X=1;

Y=[2 3 4];

Z=[1 5;2 6;3 7];

E=[] % an empty matrix

% size returns a row vector describing the dimensions of an array.

sz_X=size(X);

-> 1 1 % [1 1] 1 row, 1 column

sz_Y=size(Y);

-> 1 3 % [1 3] 1 row, 3 column

sz_Z=size(Z);

-> 3 2 % [3 2] 3 row, 2 column

sz_Z=size(E);

-> 0 0 % [0 0]

% length returns a scalar describing the largest dimension of an array.

len_X=length(X);

-> 1

len_Y=length(Y);

-> 3 % For vectors, the length is simply the number of the elements.

len_Z=length(Z);

-> 3 % For arrays with more dimensions, length(Z) is max(size(Z)).