得到 - [NSNull countByEnumeratingWithState：对象：计数：]

Question

我试图通过数组筛选并摆脱所有重复的字符串。

NSMutableArray *initialWomensCategoryArray = [NSMutableArray new]; 

    for(NSArray *womensCategoryInnner in [objects valueForKey:@"womensCategory"]) 
    { 
     for(id object in womensCategoryInnner) 
     { 

      [initialWomensCategoryArray addObject:object]; 

      womensDataArray = [[NSMutableArray alloc]init]; 
      for (id obj in initialWomensCategoryArray) 
      { 
       if (![womensDataArray containsObject:obj]) 
       { 
        [womensDataArray addObject: obj]; 
       } 
      } 
     } 
    } 

Answer 1

上述错误想说“你已经得到NULL值”，当你有对象添加到数组。所以，你必须为这个错误

1）[initialWomensCategoryArray addObject:object]

2）[womensDataArray addObject: obj]

我认为你必须检查的第一个（[initialWomensCategoryArray addObject:object]）