Use QJsonDocument to serialize/deserialize JSON. See below:
QJsonObject ingredient;
ingredient["name"] = QString("testName");
ingredient["date"] = QString("testDate");
QJsonDocument doc(ingredient);
QByteArray bytes = doc.toJson();
qDebug() << bytes;
This snippet will produce the following JSON output:
{
"date": "testDate",
"name": "testName"
}