clear
%% STRING: Create and Edit p.16
 S="Mexmat Forever!";
 S1=isletter(S);
 S2=split(S);
 [S2(1);S2(2)];
 SL=length(S2(1))==length(S2(1)); % length(S2(1))
 S3=S2(1)+" .sfedu"  % cat
 strlength(S3)
 s3=lower(S3)  % upper
 erase(s3,' ')  % s3=erase(s3,' ') 
 whos % who
%% String->Char
C=char(S) % S='Mexmat Forever!'
length(C)
CL=C(S1), CL(1:6)           % Choose letters   C(isletter(S))
%% CHAR:
a='Letter'             % According definition
a=upper('letter');
it=a(1:4)
res=isreal(imag(it))   % local  menu

%% palindrome, p. 17
clear
b='Уверен и не реву'
Lb=isletter(b)          % b1=erase(b,' '); 
b1=b(Lb)
b1=lower(b1); 
b2=fliplr(b1)
all(b1==b2)              % palindrome ?