(Delphi ActiveX) JSON: Nested Array

Here we have a JSON object that contains nested arrays. This example demonstrates how to access the contents of the nested arrays.

{
 "numbers" : [ 
    ["even", 2, 4, 6, 8], 
    ["prime", 2, 3, 5, 7, 11, 13] 
  ] }

Chilkat for Delphi Downloads Chilkat ActiveX DLL for Delphi Chilkat non-ActiveX DLL for Delphi * The examples here use the ActiveX DLL.

uses
    Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
    Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, Chilkat_TLB;

...

procedure TForm1.Button1Click(Sender: TObject);
var
json: TChilkatJsonObject;
jsonStr: WideString;
success: Integer;
outerArray: IChilkatJsonArray;
numArrays: Integer;
i: Integer;
innerArray: IChilkatJsonArray;
numInnerItems: Integer;
j: Integer;

begin
json := TChilkatJsonObject.Create(Self);

// This is the above JSON with whitespace chars removed (SPACE, TAB, CR, and LF chars).
// The presence of whitespace chars for pretty-printing makes no difference to the Load
// method. 
jsonStr := '{ "numbers" : [ ["even", 2, 4, 6, 8], ["prime", 2, 3, 5, 7, 11, 13] ] }';

success := json.Load(jsonStr);
if (success <> 1) then
  begin
    Memo1.Lines.Add(json.LastErrorText);
    Exit;
  end;

// Get the value of the "numbers" object, which is an array that contains JSON arrays.
outerArray := json.ArrayOf('numbers');
if (json.LastMethodSuccess = 0) then
  begin
    Memo1.Lines.Add('numbers array not found.');
    Exit;
  end;

numArrays := outerArray.Size;

for i := 0 to numArrays - 1 do
  begin

    innerArray := outerArray.ArrayAt(i);

    // The first item in the innerArray is a string
    Memo1.Lines.Add(innerArray.StringAt(0) + ':');

    numInnerItems := innerArray.Size;

    for j := 1 to numInnerItems - 1 do
      begin

        Memo1.Lines.Add('  ' + IntToStr(innerArray.IntAt(j)));

      end;

  end;
end;