How can i take an error without using try catch ?

Hi, My condition is something like this (()) +4 If parenthese is empty, code should give an error not only four parenthesis but also infinitive parenthesis String can use for determining error. Also parenthesis take an input with numbers.

[Azzi Abdelmalek]

What parenthesis ?

[ahmet ozdemir]

My program evaluate number like 3+4 =7 but if i give like ((()))+3+4 it should give an error since parenthesis is empty. Only empty parenthesis conditon should be thought. I hold on other type of thing like open parenthesis. It should be for empty parenthesis

[Adam]

If you are asking what your question title says then:

error( ... )

throws an error and

assert( condition, ... )

asserts that a condition is true and throws an error if it isn't. The body of your question seems to concern other matters that are potentially vastly more complicated though and seem to be effectively trying to write your own parser.

Answer 1

[Jan]

Str = '((( ))) + 3 + 4';
Str = Str(~isspace(Str));  % remove spaces
if any(strfind(Str, '()'))
  disp('Empty parenthesis found!');
end