ios - 我可以在 for 循环中将键值对添加到 NSarray 或字典吗？

Question

我想从带有键值对的 for 循环中向 NSMutabledictionary 添加值？

目前正在使用这段代码

for(int j=0;j<[array count];j++){
    for(int l=0;l<array2 count] ;l++){   
          // retreive the category from plist ,then check whether its matching with "catid"
          NSString *temp=[NSString stringWithFormat:@"%@",allBookPlist[@"listbook"][j][@"cate"][l][@"categories"]];

           if([catId isEqualToString:temp]){    
                 // "catid" is matching with temp then ,retreive the corresponding bid from plist
                 NSString *str=[NSString stringWithFormat:@"%@",allBookPlist[@"listbook"][j][@"bid"]];
                 // add that  value "bid" and key "catid" to a mutabledictionary
                 NSMutableDictionary *m=[[NSMutableDictionary alloc]init];
                 [m setValue:str forKey:catId];
            }
     }
}

结果是每次最终字典“m”的值都被最新值替换，但我希望所有值都在一起？

我正在尝试获得这样的输出

Answer 1

我想你可以将字典的初始化移到 for 之外，因为在 for 中它在每个循环中都被初始化，这就是为什么它只有一个值

NSMutableDictionary *m = [[NSMutableDictionary alloc] init];
for(int j=0; j < [array count]; j++)
{
    NSMutableArray *containerArray = [[NSMutableArray alloc] init];
    for(int l=0;l<[array2 count] ;l++)
    {
        // retreive the category from plist ,then check whether its matching with "catid"
        NSString *temp=[NSString stringWithFormat:@"%@",allBookPlist[@"listbook"][j][@"cate"][l][@"categories"]];

        if([catId isEqualToString:temp])
        {
            // "catid" is matching with temp then ,retreive the corresponding bid from plist
            NSString *str=[NSString stringWithFormat:@"%@",allBookPlist[@"listbook"][j][@"bid"]];

            // add that  value "bid" and key "catid" to a mutabledictionary
             [containerArray addObject:str];
        }
        [m setValue:containerArray forKey:catId];
    }
}

更新

我已经更新了上面的代码以适应图片中的输出