objective-c - NSString から文字列を抽出する

Question

NSString *str = [NSString stringWithString:@"The dog ate the cat"];

「で」で始まる上記の文字列から単語を抽出する方法。

Answer 1

NSArray *words = [str componentsSeparatedByString:@" "];
NSPredicate *predicate = [NSPredicate predicateWithFormat:@"SELF BEGINSWITH %@", @"at"];
NSArray *wordsStartingWithAt = [words filteredArrayUsingPredicate:predicate];

Answer 2

NSRegularExpressionクラスを使用する必要があります。

NSString *str = @"The dog ate the cat";
NSError *error = NULL;
NSRegularExpression *regex = [NSRegularExpression
                              regularExpressionWithPattern:@"(at\\w+)"
                              options:NSRegularExpressionCaseInsensitive
                              error:&error];
[regex enumerateMatchesInString:str options:0
                          range:NSMakeRange(0, str.length)
                     usingBlock:^(NSTextCheckingResult *match, NSMatchingFlags flags, BOOL *stop)
{
    NSString *result = [str substringWithRange:match.range];
    NSLog(@"%@", result);
}];