在条件语句中强制转换 NSSEt

Question

为什么不管索引 0 处的对象是否在集合中，这句话总是正确的？

smallestNumberSort 是一个 NSMutableArray

smallestNumberSet 是一个 NSSet

if ([smallestNumberSet containsObject:[NSSet setWithObject:[smallestSortComplete objectAtIndex:0]]] == NO)
         [outcome removeAllObjects];

最小代码示例

-(void)GoodCoordinates
{
   NSCountedSet *outcome   = [[NSCountedSet alloc] init]; //will contain 4 random plot point between -50 and +50
   NSMutableArray smallestSortComplete = [NSMutableArray alloc] init];
   NSSortDescriptor* sortDescriptor = [NSSortDescriptor sortDescriptorWithKey:nil ascending:YES];


   NSMutableArray smallestCoords = [NSMutableArray alloc] initwithObjects: 
      [NSNumber numberWithInt:1]
      [NSNumber numberWithInt:7]
      [NSNumber numberWithInt:-14]
      [NSNumber numberWithInt:10]
      [NSNumber numberWithInt:-21],nil];

 BOOL (inBounds = NO)
   {   

     [smallestSortComplete removeAllObjects];
    smallestSortComplete = [NSMutableArray arrayWithArray:[outcome allObjects]]; 
    [smallestSortComplete sortUsingDescriptors:[NSArray arrayWithObject:sortDescriptor]];
    
   
               
    if ([smallestCoords containsObject:[smallestSortComplete objectAtIndex:0]] == NO)
       [outcome removeAllObjects];
   else
      inBounds = YES;
}

Answer 1

让我们取消嵌套代码：

id object = [smallestSortComplete objectAtIndex:0];
NSSet *set = [NSSet setWithObject:object];
if ([smallestNumberSet containsObject:set] == NO)
    [outcome removeAllObjects];

新创建的set 对象不在smallestNumberSet 中。测试object是否在smallestNumberSet中：

id object = [smallestSortComplete objectAtIndex:0];
if ([smallestNumberSet containsObject:object] == NO)
    [outcome removeAllObjects];

或

if ([smallestNumberSet containsObject:[smallestSortComplete objectAtIndex:0]] == NO)
    [outcome removeAllObjects];