objective c - stringByTrimmingCharactersInSet: - not tripping a disalllowed '%'? -

for odd reason; stringbytrimmingcharacterinset: allows '%' through.

why ?

simple code demonstrates issue (meant phone # text):

    nsstring * allowedset = @"01234567890+-#";     nscharacterset * disallowedset =[[nscharacterset charactersetwithcharactersinstring:allowedset] invertedset];      in = @"+31%121212abc";     out = [in  stringbytrimmingcharactersinset:disallowedset]; 

i have expected output

... in  : +31%121212abc ... out : +31121212 

but getting:

... in  : +31%121212abc ... out : +31%121212 

why ? seems work pretty other chars. '%' special - or odd url related issue ?

i trimming string; opposed replacing chars. ignores not @ start or end; i.e. chars in middle of string. using stringbyreplacingcharactersinset: resolves nicely.

@interface nsstring (inefficientstringbyremovingcharactersinset) - (nsstring *)stringbyremovingcharactersinset:(nscharacterset *)characterset; @end  @implementation nsstring (inefficientstringbyremovingcharactersinset) - (nsstring *)stringbyremovingcharactersinset:(nscharacterset *)characterset {     return [[self componentsseparatedbycharactersinset:characterset]        componentsjoinedbystring:@""]; } @end