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i need to store a two strings in an Array like this, and retrieve values in another function to use it.

Date Start Date End
VALUE_START VALUE_END
VALUE_START2 VALUE_END2

I think the correct ways is to use this variable StoringData : TArray<String>, but how can i valorized it with VALUE_START and VALUE_END ?

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  • type TPeriod = record StartDate, EndDate: TDate; end and var Data: array[0..1] of TPeriod if you want a static array and var Data: TArray<TPeriod> if you want a dynamic array. Remember that dynamic arrays are reference types. Or, use a TList<TPeriod> if you want a simpler API to work against and can live with having to create and free the list heap object. Commented May 28, 2021 at 9:01
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    And I might also advice you to buy a good book about Delphi programming and read it carefully so you learn the language properly! Commented May 28, 2021 at 9:15

2 Answers 2

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First you have to define a data type that can hold two string:

type
    TPeriod = record
        DateStart : String;     // Isn't TDateTime better than String here ?
        DateEnd   : String;
    end;

Then you can declare a dynamic array if that data type

var
    StoringData : TArray<TPeriod>;

At some point, you must allocate space for the array (This is a dynamic array so no space allocated when it is declared)

SetLength(StoringData, TheSizeYouNeed);

The you can access the array elements like this:

StoringData[0].DateStart := '04/05/2021';
StoringData[0].DateEnd   := '06/05/2021';
StoringData[1].DateStart := '04/06/2021';
StoringData[1].DateEnd   := '06/06/2021';

You don't need to free the allocated space, it will be done automatically, but you can if you need to reclaim memory. Call SetLength with a zero size.

You can resize the array. Existing data will be kept (If you size down, some will of course be lost):

SetLength(StoringData, 3);   // Add a third more row
// Assign a value
StoringData[2].DateStart := '04/07/2021';
StoringData[2].DateEnd   := '06/07/2021';
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10 Comments

That's what I was looking for, my code right now is this StoringData : TArray<String>; SetLength(StoringData,2); for x := 0 to High(StoringData) do for c := 0 to High(StoringData[x]) do begin StoringData[x] := DataCovertedS; StoringData[c] := TotTime; ` end;`
No need for a record type. Use a 2-dimensional array instead, if you like
@DelphiCoder Yes 2D array, but i'm not able to store [c] on the second column do you know why ?
A record is much better than a 2D array: a record can have methods ! For example, you can add a method to initialize the record at once, or to get/set the values from/to TDateTime and much more. Also with a record, you can easily add more members without breaking existent code. Records in Delphi are first class citizen, much like classes. 2D array are old school.
@Marcol1no I edited my answer to add a resize example (adding a 3rd row).
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Make a 2-dimensional array with the first dimension being dynamic, and the second one static:

TYPE
  TPeriod = ARRAY[1..2] OF STRING;
  TPeriods = TArray<TPeriod>;

VAR
  Periods : TPeriods;

BEGIN
  SetLength(Periods,2);
  Periods[0,1]:='Start Date 1';
  Periods[0,2]:='End Date 1';
  Periods[1,1]:='Start Date 2';
  Periods[1,2]:='End Date 2';
END.
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1 Comment

Much less readable than a record, much more prone to errors.

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