Cannot access child value on newtonsoft.json.linq.jproperty.

When you encounter the error “cannot access child value on newtonsoft.json.linq.jproperty”, it means that you are trying to access the value of a child property using the JProperty class in Newtonsoft.Json.Linq but the property you are trying to access does not exist.

To better understand this error, let’s consider an example:

// JSON string
  string json = "{\"name\":\"John\", \"age\":30, \"city\":\"New York\"}";
  
  // Parse the JSON string
  JObject jObject = JObject.Parse(json);
  
  // Access a child property value
  int age = (int)jObject["age"]; // This will work
  
  // Try to access a non-existent child property value
  string country = (string)jObject["country"]; // This will throw the error

In the above example, we have a JSON string with properties “name”, “age”, and “city”. We successfully access the value of the “age” property using jObject[“age”]. However, when we try to access the non-existent “country” property, the error “cannot access child value on newtonsoft.json.linq.jproperty” is thrown.

To avoid this error, you need to ensure that the child property you are trying to access actually exists in the JSON object. You can do so by checking if the property is null before accessing its value:

// Check if the property exists before accessing its value
  JToken countryToken = jObject["country"];
  if (countryToken != null)
  {
      string country = (string)countryToken;
      // Use the country value
  }
  else
  {
      // Property does not exist
  }

In the updated example, we first check if the “country” property exists by assigning it to a JToken variable. If the property is not null, it means it exists, and we can safely access its value. Otherwise, we handle the case when the property does not exist.

By following this approach, you can avoid the “cannot access child value on newtonsoft.json.linq.jproperty” error and handle cases where certain properties might be missing in the JSON object.