regexp problem in '.'

I have a string and I want to split it with '.', but the regexp does not work.

test='abcde.abcde';
regexp(test,'.','split')

but it does not work, the result is a 1*12 cell array.

however, if I replace the '.' with other symbol, such as '_', the regexp function works properly.

test='abcde_abcde';
regexp(test,'_','split')

just want know if there is any mistake with my operation? or, is this a feature in 'regexp' function?

Thanks!

Yu

Answer 1

[per isakson]

Try

%%
test='abcde.abcde';
regexp(test,'\.','split')

returns

ans =
  1×2 cell array
    {'abcde'}    {'abcde'}
    

dot stands for any single character. An escape is needed to a literal dot.

[Yu Li]

Thank for your answer, the problem has been solved.

could you please explain why this happens and why your answer works?

Thanks!

Yu

[per isakson]

dot is a Metacharacters, see the documentaion, which says:

. Any single character, including white space, '..ain' matches sequences of five consecutive characters that end with 'ain'.

[Yu Li]

Thank you!

Bests,

Yu