QtにおいてECMAScriptを実行し、その結果をJSONで受け取ること。

main.cxx

#include <QGuiApplication>
#include <QQmlApplicationEngine>
#include <QtScript>

int main(int argc, char *argv[]) {
  QGuiApplication app(argc, argv);

  QQmlApplicationEngine appEngine;
  appEngine.load(QUrl(QStringLiteral("qrc:/main.qml")));

  QScriptEngine scriptEngine;
  QString script = "var x = { a: true, b: 'c', c: 7, d: [ 1, 2, 3 ] }; JSON.stringify(x, null, 2);";

  QJsonDocument json = QJsonDocument::fromJson(scriptEngine.evaluate(script).toString().toUtf8());
  QJsonObject x = json.object();
  qDebug() << "a: " << x["a"].toBool() << ", b: " << x["b"].toString() << ", c: " << x["c"].toInt();
  auto arr = x["d"].toArray();
  qDebug("d:");
  for (int i = 0; i < arr.size(); i++) {
    qDebug() << "    " << arr[i].toInt();
  }

  return app.exec();
}