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新数组每个循环迭代(New Array Every Loop Iteration)

 我需要在循环的每次迭代中声明一个新数组，我知道我可以通过以下方式执行：  
//Store mappings from array name (String) to int arrays (int[])
Map<String, int[]> namedArrays = new HashMap<String, int[]>();
for (int i = 0; i < 3; i++)
{
  //This is going to be the name of your new array
  String arrayName = String.valueOf(i); 
  //Map an new int[] to this name
  namedArrays.put(arrayName, new int[3]);
}

//If you need to access array called "2" do
int[] array2 = namedArrays.get("2");
 
 我的问题是在我声明一个新数组的部分，如果有一个已经命名为ai[]的数组，我可以像这样直接初始化它吗？：  
namedArrays.put(arrayName,ai);
 
 我试过这个但是我收到了一个错误。  
 编辑：现在我明白我实际上有一个检索数组的问题我按以下方式初始化。  
Map<String, int[]> namedArrays = new HashMap<String, int[]>();

        for(int i=0;i<testCase;i++){
            int num=scanner.nextInt();
            int[] ai=new int[num];
            for(int j=0;j<num;j++){
                ai[j]=scanner.nextInt();

            }
             String arrayName = String.valueOf(i); 

             namedArrays.put(arrayName,ai);
 
 我试图通过以下方式检索它  
for(int i=0;i<testCase;i++){
            int[] array2 = namedArrays.get(i);
 
 array2包含类似“[I @ 1fc4bec”的值。 但它应该包含一个数组。  
 编辑2：我明白我可以通过以下方式获得阵列  
String arrayName = String.valueOf(i); 
            // System.out.println(namedArrays.get(arrayName)[0]);
            int b=namedArrays.get(arrayName).length;
            int[] array2=new int[b];
            for(int z=0;z<b;z++){
            array2[z] = namedArrays.get(arrayName)[z];}
 
 但是，确实如此  
array2[z] = namedArrays.get(arrayName)
 
 回归“[I @ 1fc4bec”？ 

I need to declare a new array every iteration of the loop, I understand I can do it the following way:  
//Store mappings from array name (String) to int arrays (int[])
Map<String, int[]> namedArrays = new HashMap<String, int[]>();
for (int i = 0; i < 3; i++)
{
  //This is going to be the name of your new array
  String arrayName = String.valueOf(i); 
  //Map an new int[] to this name
  namedArrays.put(arrayName, new int[3]);
}

//If you need to access array called "2" do
int[] array2 = namedArrays.get("2");
 
My question is at the part where I declare a new array, what if have a array already named ai[],can I initialize it directly like this?: 
namedArrays.put(arrayName,ai);
 
I tried this but I am getting an error. 
EDIT: Now I understand I actually have a problem with retrieving the array I initialized the following way. 
Map<String, int[]> namedArrays = new HashMap<String, int[]>();

        for(int i=0;i<testCase;i++){
            int num=scanner.nextInt();
            int[] ai=new int[num];
            for(int j=0;j<num;j++){
                ai[j]=scanner.nextInt();

            }
             String arrayName = String.valueOf(i); 

             namedArrays.put(arrayName,ai);
 
I am trying to retrieve it the following way  
for(int i=0;i<testCase;i++){
            int[] array2 = namedArrays.get(i);
 
array2 contains value something like "[I@1fc4bec". But it is supposed to contain an array. 
EDIT 2 : I understood that I can get the array the following way  
String arrayName = String.valueOf(i); 
            // System.out.println(namedArrays.get(arrayName)[0]);
            int b=namedArrays.get(arrayName).length;
            int[] array2=new int[b];
            for(int z=0;z<b;z++){
            array2[z] = namedArrays.get(arrayName)[z];}
 
But y does  
array2[z] = namedArrays.get(arrayName)
 
return "[I@1fc4bec" ?

原文：https://stackoverflow.com/questions/38182869

更新时间：2021-03-10 12:03

最满意答案

-- This Section is Just to Stage some Sample Data
--------------------------------------------------------------------------------------------------------
Declare @Inv table (SKU int,FirstReceiptDate Date,LastReceiptDate Date,OnHand int,SalesUnits int)
Insert Into @Inv (SKU,FirstReceiptDate,LastReceiptDate,OnHand,SalesUnits) values
(456,'2014-03-15','2014-12-14',0,15),
(789,'2014-05-30','2014-12-15',10,35),
(321,'2014-07-31','2016-03-16',112,60)

Declare @Hier table (SKU int,PtSKU int,PS int,Title varchar(50)) 
Insert into @Hier (SKU,PtSKU,PS,Title) values
(123,0,0,'SKU Tile 123'),
(456,123,10,'Some Other Title SKU 456'),
(789,123,20,'This is the Title for Title SKU 786'),
(321,123,30,'Finally Tile 321')


-- This Section Builds the Hierarchy with Range Keys  Hierarchies can be variable depth
-- My hierarchies are pretty static so they are rebuilt as needed
-- The real power is using the range key.  You can aggregate data without 
-- a recursive query.
-- I should not that I added a Presentation Sequence (PS) and Title to the Hierarcy
-- The PS is used to control the presentation order.  This can be alphabetical as well
--------------------------------------------------------------------------------------------------------
;With cteOH (SKU,PtSKU,Lvl,PS,SortSeq) as 
     (
        Select SKU,PtSKU,Lvl=1,PS,cast([dbo].[udf-Str-PadL](PS,0,6) +':' +[dbo].[udf-Str-PadL](SKU,0,6) + '/' as varchar(500)) from @Hier where  PtSKU=0
        Union All
        Select h.SKU,h.PtSKU,cteOH.Lvl+1,h.PS,SortSeq=cast(cteOH.SortSeq + [dbo].[udf-Str-PadL](H.PS,0,6) +':' +[dbo].[udf-Str-PadL](H.SKU,0,6) + '/' as varchar(500)) FROM @Hier h INNER JOIN cteOH ON  h.PtSKU = cteOH.SKU
     )
    ,cteR1  as (Select SKU,SortSeq,R1=Row_Number() over (Order by SortSeq) From cteOH)
    ,cteR2  as (Select A.SKU,R2 = max(B.R1) From cteOH A Join cteR1 B on (B.SortSeq Like A.SortSeq+'%') Group By A.SKU)
    Select B.R1
          ,C.R2
          ,A.Lvl
          ,A.SKU
          ,A.PtSKU
          ,A.PS
          ,T.Title
     Into  #TempOH
     From  cteOH A
     Join  cteR1 B on (A.SKU=B.SKU)
     Join  cteR2 C on (A.SKU=C.SKU)
     Join  @Hier T on (A.SKU=T.SKU)
     Order By B.R1


-- This Section illustrates how to aggregate data via the range keys
--------------------------------------------------------------------------------------------------------
Select A.*  
      ,FirstReceiptDate       = min(B.FirstReceiptDate)
      ,LastReceiptDate        = max(B.LastReceiptDate)
      ,OnHand                 = sum(B.OnHand)
      ,SalesUnits             = sum(B.SalesUnits)
      ,MonthsSupply           = cast(sum(B.OnHand*12.)/sum(B.SalesUnits) as money)
      ,FamilyFirstReceiptDate = First_Value(min(B.FirstReceiptDate)) Over (Order By A.R1)
      ,FamilyLastReceiptDate  = First_Value(max(B.LastReceiptDate))  Over (Order By A.R1)
      ,FamilyOnHand           = First_Value(sum(B.OnHand))           Over (Order By A.R1)
      ,FamilySalesUnits       = First_Value(sum(B.SalesUnits))       Over (Order By A.R1)
      ,FamilyMonthsSupply     = First_Value(cast(sum(B.OnHand*12.)/sum(B.SalesUnits) as money))       Over (Order By A.R1)
 From #TempOH A
 Join (Select _R1=B.R1,A.* From @Inv A Join #TempOH B on A.SKU=B.SKU) B on _R1 between A.R1 and A.R2
 Group By A.R1,A.R2,A.Lvl,A.SKU,A.PtSKU,A.PS,A.Title
 Order By A.R1
 
 返回  
R1                   R2                   Lvl         SKU         PtSKU       PS          Title                                              FirstReceiptDate LastReceiptDate OnHand      SalesUnits  MonthsSupply          FamilyFirstReceiptDate FamilyLastReceiptDate FamilyOnHand FamilySalesUnits FamilyMonthsSupply
-------------------- -------------------- ----------- ----------- ----------- ----------- -------------------------------------------------- ---------------- --------------- ----------- ----------- --------------------- ---------------------- --------------------- ------------ ---------------- ---------------------
1                    4                    1           123         0           0           SKU Tile 123                                       2014-03-15       2016-03-16      122         110         13.3091               2014-03-15             2016-03-16            122          110              13.3091
2                    2                    2           456         123         10          Some Other Title SKU 456                           2014-03-15       2014-12-14      0           15          0.00                  2014-03-15             2016-03-16            122          110              13.3091
3                    3                    2           789         123         20          This is the Title for Title SKU 786                2014-05-30       2014-12-15      10          35          3.4286                2014-03-15             2016-03-16            122          110              13.3091
4                    4                    2           321         123         30          Finally Tile 321                                   2014-07-31       2016-03-16      112         60          22.40                 2014-03-15             2016-03-16            122          110              13.3091
 
 所需功能  
CREATE FUNCTION [dbo].[udf-Str-PadL] (@Value varchar(50),@Pad varchar(10) = '0',@Len int = 10)

-- Syntax : Select [dbo].[udf-Str-PadL](25,0,10)
-- Syntax : Select [dbo].[udf-Str-PadL](25,'-',6)

Returns varchar(50)
AS
  BEGIN
    Return right(concat(Replicate(@Pad,@Len),@Value),@Len)
  END

-- This Section is Just to Stage some Sample Data
--------------------------------------------------------------------------------------------------------
Declare @Inv table (SKU int,FirstReceiptDate Date,LastReceiptDate Date,OnHand int,SalesUnits int)
Insert Into @Inv (SKU,FirstReceiptDate,LastReceiptDate,OnHand,SalesUnits) values
(456,'2014-03-15','2014-12-14',0,15),
(789,'2014-05-30','2014-12-15',10,35),
(321,'2014-07-31','2016-03-16',112,60)

Declare @Hier table (SKU int,PtSKU int,PS int,Title varchar(50)) 
Insert into @Hier (SKU,PtSKU,PS,Title) values
(123,0,0,'SKU Tile 123'),
(456,123,10,'Some Other Title SKU 456'),
(789,123,20,'This is the Title for Title SKU 786'),
(321,123,30,'Finally Tile 321')


-- This Section Builds the Hierarchy with Range Keys  Hierarchies can be variable depth
-- My hierarchies are pretty static so they are rebuilt as needed
-- The real power is using the range key.  You can aggregate data without 
-- a recursive query.
-- I should not that I added a Presentation Sequence (PS) and Title to the Hierarcy
-- The PS is used to control the presentation order.  This can be alphabetical as well
--------------------------------------------------------------------------------------------------------
;With cteOH (SKU,PtSKU,Lvl,PS,SortSeq) as 
     (
        Select SKU,PtSKU,Lvl=1,PS,cast([dbo].[udf-Str-PadL](PS,0,6) +':' +[dbo].[udf-Str-PadL](SKU,0,6) + '/' as varchar(500)) from @Hier where  PtSKU=0
        Union All
        Select h.SKU,h.PtSKU,cteOH.Lvl+1,h.PS,SortSeq=cast(cteOH.SortSeq + [dbo].[udf-Str-PadL](H.PS,0,6) +':' +[dbo].[udf-Str-PadL](H.SKU,0,6) + '/' as varchar(500)) FROM @Hier h INNER JOIN cteOH ON  h.PtSKU = cteOH.SKU
     )
    ,cteR1  as (Select SKU,SortSeq,R1=Row_Number() over (Order by SortSeq) From cteOH)
    ,cteR2  as (Select A.SKU,R2 = max(B.R1) From cteOH A Join cteR1 B on (B.SortSeq Like A.SortSeq+'%') Group By A.SKU)
    Select B.R1
          ,C.R2
          ,A.Lvl
          ,A.SKU
          ,A.PtSKU
          ,A.PS
          ,T.Title
     Into  #TempOH
     From  cteOH A
     Join  cteR1 B on (A.SKU=B.SKU)
     Join  cteR2 C on (A.SKU=C.SKU)
     Join  @Hier T on (A.SKU=T.SKU)
     Order By B.R1


-- This Section illustrates how to aggregate data via the range keys
--------------------------------------------------------------------------------------------------------
Select A.*  
      ,FirstReceiptDate       = min(B.FirstReceiptDate)
      ,LastReceiptDate        = max(B.LastReceiptDate)
      ,OnHand                 = sum(B.OnHand)
      ,SalesUnits             = sum(B.SalesUnits)
      ,MonthsSupply           = cast(sum(B.OnHand*12.)/sum(B.SalesUnits) as money)
      ,FamilyFirstReceiptDate = First_Value(min(B.FirstReceiptDate)) Over (Order By A.R1)
      ,FamilyLastReceiptDate  = First_Value(max(B.LastReceiptDate))  Over (Order By A.R1)
      ,FamilyOnHand           = First_Value(sum(B.OnHand))           Over (Order By A.R1)
      ,FamilySalesUnits       = First_Value(sum(B.SalesUnits))       Over (Order By A.R1)
      ,FamilyMonthsSupply     = First_Value(cast(sum(B.OnHand*12.)/sum(B.SalesUnits) as money))       Over (Order By A.R1)
 From #TempOH A
 Join (Select _R1=B.R1,A.* From @Inv A Join #TempOH B on A.SKU=B.SKU) B on _R1 between A.R1 and A.R2
 Group By A.R1,A.R2,A.Lvl,A.SKU,A.PtSKU,A.PS,A.Title
 Order By A.R1
 
Returns 
R1                   R2                   Lvl         SKU         PtSKU       PS          Title                                              FirstReceiptDate LastReceiptDate OnHand      SalesUnits  MonthsSupply          FamilyFirstReceiptDate FamilyLastReceiptDate FamilyOnHand FamilySalesUnits FamilyMonthsSupply
-------------------- -------------------- ----------- ----------- ----------- ----------- -------------------------------------------------- ---------------- --------------- ----------- ----------- --------------------- ---------------------- --------------------- ------------ ---------------- ---------------------
1                    4                    1           123         0           0           SKU Tile 123                                       2014-03-15       2016-03-16      122         110         13.3091               2014-03-15             2016-03-16            122          110              13.3091
2                    2                    2           456         123         10          Some Other Title SKU 456                           2014-03-15       2014-12-14      0           15          0.00                  2014-03-15             2016-03-16            122          110              13.3091
3                    3                    2           789         123         20          This is the Title for Title SKU 786                2014-05-30       2014-12-15      10          35          3.4286                2014-03-15             2016-03-16            122          110              13.3091
4                    4                    2           321         123         30          Finally Tile 321                                   2014-07-31       2016-03-16      112         60          22.40                 2014-03-15             2016-03-16            122          110              13.3091
 
Required function 
CREATE FUNCTION [dbo].[udf-Str-PadL] (@Value varchar(50),@Pad varchar(10) = '0',@Len int = 10)

-- Syntax : Select [dbo].[udf-Str-PadL](25,0,10)
-- Syntax : Select [dbo].[udf-Str-PadL](25,'-',6)

Returns varchar(50)
AS
  BEGIN
    Return right(concat(Replicate(@Pad,@Len),@Value),@Len)
  END

新数组每个循环迭代(New Array Every Loop Iteration)

最满意答案

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