为什么我的NSMutableDictionary会为零？

Question

我正在尝试将数组存储在NSMutableDictionary中。但是，在我将对象设置为它之后，NSMutableDictionary为null。这是我的代码，任何帮助表示赞赏：

NSMutableArray *arrTemp = [[NSMutableArray alloc] init];
NSMutableDictionary *dTemp = [[NSMutableDictionary alloc] init];
STStockData *stockData = [[STStockData alloc] init];
for (int i = 0; i < [_arrTickers count]; i++) {
    // get the ticker from its json form
    dTemp = [_arrTickers objectAtIndex:i];
    NSLog(@"Ticker: %@",[dTemp objectForKey:@"ticker"]);
    // gets current data for ticker
    [arrTemp addObjectsFromArray:[stockData getCurrentStockDataForTicker:[dTemp objectForKey:@"ticker"]]];
    NSLog(@"Price %@",[arrTemp objectAtIndex:1]); // just to prove the array isnt nil.
    // adds it to the dictionary
    [_dStockData setObject:arrTemp forKey:[dTemp objectForKey:@"ticker"]];
    NSLog(@"Dictionary %@",_dStockData);
    // remove all objects so can reuse.
    [arrTemp removeAllObjects];
    dTemp = nil; // can't remove objects using [removeAllObjects] method. believe its due to it holding inside NSArrays which are immutable.

}

这是控制台输出：

Answer 1

初始化_dStockData

_dStockData = [[NSMutableDictionary alloc] init];

Answer 2

它是零，因为使用初始化stockData

STStockData *stockData = [[STStockData alloc] init];

并打印_dStockData

NSLog(@"Dictionary %@",_dStockData);