behavior of for loop with strings of chars ?

Hi, this for statement

        for string = ['=A=', '=B=', '=C=']
            [starts, ends] = regexp(line, string);

the strings read as single '=' character in regexp ; as = is not a special character according to regexp, there is no need to precede it with \, as in '\=A\=' ? I tried some solutions using additional variables to represent those strings, or sprintf, but it didn't work ... Can somebody help me ? Thank you

[Stephen23]

In MATLAB [] is simply a concatenation operator, so this:

['=A=', '=B=', '=C=']

is exactly equivalent to this:

'=A==B==C='

Then the for loop will simply iterate over each element (i.e. character) of that character vector. I would recommend only using indices for the loop iterator, rather than characters/cells/strings/...

It is not clear from your code what you are trying to achieve. Rather than showing us your buggy solution, it would be more helpful to explain what you are actually trying to achieve.

http://xyproblem.info/

[genevois pierre]

thank you for your comment, as you advise me, i will use numeral values in the for statement.

[TADA]

I think that still won't cut it.

you will probably want to switch from a vector to a cell array of character vectors

patterns = {'=A=' '=B=' '=C='};
for i = 1:length(patterns)
[starts, ends] = regexp(line, patterns{i});
end

[genevois pierre]

Thank you TADA : it works !

[Stephen23]

Depending on lines, the for is possibly superfluous:

patterns = {'=A=','=B=','=C='};
[starts,ends] = regexp(line,patterns);

[genevois pierre]

thank you ; I think that this question can be closed now, but I don't see the button to close it ...

[TADA]

there should be an accept answer somewhere

Come to think of it, I don't know exactly how you build your pattern there and if it really is a simple pattern as you wrote here, but a single pattern can easily cope with all three letters

regexp(line, '=[ABC]=')

[Guillaume]

The best thing would be for TADA to write his answer as an actual answer so that pierre can accept it. You can't accept comments.

The question should not be closed as it would no longer be visible. It contains useful information.

Answer 1

[TADA]

you will probably want to switch from a vector to a cell array of character vectors

patterns = {'=A=' '=B=' '=C='};
for i = 1:length(patterns)
[starts, ends] = regexp(line, patterns{i});
end

or better yet like Stephen Cobeldick mentioned, send the cell array over to regexp

patterns = {'=A=' '=B=' '=C='};
[starts, ends] = regexp(line, patterns);

or just put it all in a single pattern

[starts, ends] = regexp(line, '=[ABC]=');