iOS开发之NSArray的过滤

         iOS开发之NSArray的过滤

　　//找出一个数组

　　NSFileManager *fileManager = [NSFileManager defaultManager];

　　NSString *defaultPath = [[NSBundle mainBundle] resourcePath];

　　NSError *error;

　　NSArray *directoryContents = [fileManager contentsOfDirectoryAtPath:defaultPath error:&error]

　　//匹配字符串，反回结果， SELF==表示数组中每一个元素

　　NSString *match = @"imagexyz-999.png";

　　NSPredicate *predicate = [NSPredicate predicateWithFormat:@"SELF == %@", match];

　　NSArray *results = [directoryContents filteredArrayUsingPredicate:predicate];

　　//近似匹配字符串，类似SQL中的语法

　　NSString *match = @"imagexyz*.png";

　　NSPredicate *predicate = [NSPredicate predicateWithFormat:@"SELF like %@", match];

　　NSArray *results = [directoryContents filteredArrayUsingPredicate:predicate];

　　//不区分大小写匹配

　　NSString *match = @"imagexyz*.png";

　　NSPredicate *predicate = [NSPredicate predicateWithFormat:@"SELF like[cd] %@", match];

　　NSArray *results = [directoryContents filteredArrayUsingPredicate:predicate];

　　//正则匹配

　　NSString *match = @"imagexyz-\d{3}\.png";

　　NSPredicate *predicate = [NSPredicate predicateWithFormat:@"SELF matches %@", match];

　　NSArray *results = [directoryContents filteredArrayUsingPredicate:predicate];