NSMutableCharacterSet *checkCharSet = [[NSMutableCharacterSet alloc] init]; [checkCharSet addCharactersInString:@"abcdefghijklmnopqrstuvwxyz"]; [checkCharSet addCharactersInString:@"ABCDEFGHIJKLMNOPQRSTUVWXYZ"]; [checkCharSet addCharactersInString:@"1234567890"]; if([[filename stringByTrimmingCharactersInSet:checkCharSet] length] > 0){ //エラー処理 } [checkCharSet release]; 上のサンプルでは、チェック対象となる変数は、NSStri