get char between two specified characters

I have a string like '[Hello]'. Now I want to get only the text between the brackets []. The result should be 'Hello'. When the string is '(Hello)' the result should be empty.

I tried with regexp but was not successfully.

regexp('[Hello]', '(\w)')
ans = 2 3 4 5 6

But I get the same result with normal brackets in the string

regexp('(Hello)', '(\w)')
ans = 2 3 4 5 6

Can anyone help me?

Answer 1

[Azzi Abdelmalek]

p='[Hello\]'
s={'[Hello]','(Hello)','[Hello]erz'}
r=regexp(s,p,'match')
r=r(cellfun(@(x) ~isempty(x),r))
out=cellfun(@(x) x{1}(2:end-1),r,'un',0)