Alternatives to substr without Stateflow?

I was trying to make a sub string and searched and found this.

https://se.mathworks.com/help/stateflow/ref/substr.html

However this seem to require Stateflow, which I don't have...

https://se.mathworks.com/help/stateflow/ug/differences-between-matlab-and-stateflow-action-language.html

Trying to make my own way(implementation?) using

https://se.mathworks.com/help/matlab/ref/convertstringstochars.html

https://se.mathworks.com/help/matlab/ref/strfind.html

https://se.mathworks.com/help/matlab/ref/strcat.html

string = "This should really be in the MatLab core!";
%convert to character array
b = convertStringsToChars(string);
ba = length(b);

%get index of "in the"
k = strfind(b,"in the");

stringbuilder = "";
%start the loop from k
for cIx = k:ba
    %sprintf because spaces will be ignored otherwise
    stringbuilder = strcat(stringbuilder,sprintf("%s",b(cIx)));
end
disp(stringbuilder);

Result:

in the MatLab core!

---

Is there another way?

Answer 1

[Ameer Hamza]

char arrays support indexing. Also, string is the name of MATLAB built-in function, so I named the name of the variable to 'str'

str = "This should really be in the MatLab core!";
%convert to character array
b = char(str); % you can simply use char()
ba = length(b);
%get index of "in the"
k = strfind(b,"in the");
stringbuilder = b(k:end);
stringbuilder = string(stringbuilder); % convert back to string

Result

>> stringbuilder
stringbuilder = 
    "in the MatLab core!"

[Erik Taurus]

Excellent, neat and tidy, thank you!

[Ameer Hamza]

I am glad to be of help.

[Erik Taurus]

If anyone else read this I found out that MatLab does have this built in, but in three different core functions

https://se.mathworks.com/help/matlab/ref/extractbefore.html

https://se.mathworks.com/help/matlab/ref/extractbetween.html

https://se.mathworks.com/help/matlab/ref/extractafter.html

extractbetween example:

str = "Perhaps I should read the documentation before posting questions!";
startStr = strfind(str,"I ");
endStr =  strfind(str,"before")-1;
newStr = extractBetween(str,startStr,endStr);
fprintf("%s\r",newStr);