%% Cell Char String p.18
A={'Mercury','Gemini','Appolo';...
    'Skylab', 'Skylab B', 'ISS'}     % What it means?
A{end}
A{2,2}(1:3)
%%  cell->string 
str=string(A), str(1,2)
%% cell->char
B=str2mat(A)                    % old version, space added to each row
B=char(A)                       % the second way
 
%% You need to explain mistake and fix it!
clear A;
% A=['Mercury','Gemini','Appolo';...
%             'Skylab', 'Skylab B', 'ISS']
%% Analysis and Edition p.19
C={'my mind is strong'; 'my mind is resting'}
%[ind]=findstr(C{1},'mind')      % old version
[ind]=strfind(C{1},'mind')
S=[C{1},C{2}];           % What  class does S belong to? length(S) == (?)  
CS=string(C) % size CS?
[Ced,ind1]=unique(S);    % without repetition
S(ind1)==Ced % all(S(ind1)==Ced)
[Ced,ind1]=unique(CS); % the only two elements
%% comparison Char String
TF=strcmp(C{1},C{2})  % == or ~=
logicalVector=C{1}==C{2}(1:end-1)        % eq(S1,S2) need the same length
logicalVector=C{1}==C{2}    % mistake: different length
TF=strcmpi(C{1},C{2})       % Char: full comparison, for any length
%____________________________
TF=strcmpi(CS(1),CS(2))   % each element - string
TF=strcmpi(C(1),C(2))     % each element - cell
% compare n elements
TF=strncmp(C{1},C{2}(1:end-1),11)
%% p.20 You can copy the code and implement it  step by step!
%% Important! Convert Char to  ASCCI code
res=double('xyz')