str = 'Find the starting indices of a pattern in a character vector'; k = strfind(str,'in') gives, k = 2 15 19 40
any shortcut/direct way to get the first occurrence only. Here in this case: k = 2;

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Guillaume
Guillaume 2016년 5월 19일

2 개 추천

You could use regexp with the 'once' option:
k = regexp(str, 'in', 'once')
However, note that some characters have special meanings in regular expression, so if your search string is completely arbitrary you can't just replace strfind with regexp. For safety you can regexptranslate the search string.
On the other hand, what's stopping you from writing:
k = strfind(str, 'in); k = k(1);
If writing two instructions instead of one bother you, you can always create your own function:
function location = strfindfirst(lookin, lookfor)
location = strfind(lookin, lookfor);
if ~isempty(idx)
location = location(1);
end
end

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Peter
Peter 2019년 9월 27일
While the suggested answer works, it is inefficient. If you have very long strings to search through and/or have many strings to search, finding all of the occurances first, and then truncating the answer to just to first one, is a waste. Its too bad that strfind doesn't have a 'first' or 'last' option like 'find'.

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도움말 센터File Exchange에서 Characters and Strings에 대해 자세히 알아보기

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