1.刪掉字符串中最後一個字符數組
-(NSString *)descriptionWithLocale:(id)locale{ NSMutableString *str = [NSMutableString string]; [str appendString:@"(\n"]; //遍歷數組裏的全部元素 [self enumerateObjectsUsingBlock:^(id _Nonnull obj, NSUInteger idx, BOOL * _Nonnull stop) { [str appendFormat:@"\t%@,\n",obj]; }]; [str appendString:@")"]; //查出最後一個','的範圍 NSRange range = [str rangeOfString:@"," options:NSBackwardsSearch]; if (range.length != 0) { //刪掉最後一個',' [str deleteCharactersInRange:range]; } return str; }