JsonNaming.dpr

program JsonNaming;
{$APPTYPE CONSOLE}
{$R *.res}

uses
  System.Classes,
  System.SysUtils,
  REST.Json,
  REST.Json.Types,
  JsonNaming.Foo in 'JsonNaming.Foo.pas';

begin
  try
    // ommiting proper memory management here for simplicity
    var LFoo := TFoo.Create;
    LFoo.Bar := 'Bar';
    LFoo.Name := 'Foo';

    // Object to Json
    var LFooJson := TJson.ObjectToJsonString(LFoo);
    Assert(LFooJson = '{"bar":"Bar","FName":"Foo"}');

    // Json to Object
    LFoo := TJson.JsonToObject<TFoo>(LFooJson);
    Assert(LFoo.Bar = 'Bar');
    Assert(LFoo.Name = 'Foo');
  except
    on E: Exception do
      writeln(E.ClassName, ': ', E.Message);
  end;

end.

JsonNaming.Foo.pas

unit JsonNaming.Foo;

interface

uses
  System.Classes, System.SysUtils,
  REST.Json.Types;

type
  TFoo = class(TObject)
  private
    // Default naming strategy: cutting off leading "F", and making it lowerCamelCase
    FBar: string;

    // Custom naming
    [JSONName('FName')]
    FName: string;
  public
    property Bar: string read FBar write FBar;
    property Name: string read FName write FName;
  end;

implementation

end.