Objective C如何检测NSString中的一个或多个空格

NSString *string = @"Hello World   ";
NSError *error = nil;
NSRegularExpression *regex = [NSRegularExpression regularExpressionWithPattern:@"\\s+" options:0 error:&error];
NSArray *matches = [regex matchesInString:string options:0 range:NSMakeRange(0, string.length)];
BOOL hasSpaces = (matches.count > 0);

NSString *string = @"Hello World   ";
NSRange range = [string rangeOfString:@" "];
BOOL hasSpaces = (range.location != NSNotFound);

NSString *string = @"Hello World   ";
NSArray *components = [string componentsSeparatedByString:@" "];
BOOL hasSpaces = (components.count > 1);