BTD Mod Helper contains ways to easily convert an object to a JSON string, and vice versa

for System.Object

SerializeJson<T>((T objectToSerialize, bool shouldIndent = true, bool ignoreNulls = false)

same as above but allows you to put in a JsonSerializerSettings

SerializeJson<T>(T objectToSerialize, JsonSerializerSettings serializerSettings, bool shouldIndent = true)

same as above, but this time instead of returning a string it logs it to a specified savePath

SaveToFile<T>(T jsonObject, string savePath, JsonSerializerSettings serializerSettings, bool shouldIndent = true, bool overwriteExisting = true)

for Il2CppSystem.Object

Il2CppSerializeJson<T>(T il2cppObject, bool shouldIndent = true)

does the above but instead of returning a string it logs it to a specified savePath

Il2CppSaveToFile<T>(T jsonObject, string savePath, bool shouldIndent = true, bool overwriteExisting = true)

you can also use Ninja Kiwi's own logger, using the Assets.Scripts.Utils.FileIOUtil.

FileIOUtil.LogToFile("filepath.json", obj);

(this will log it to C:\Users\<username>\AppData\LocalLow\Ninja Kiwi\BloonsTD6)

doing the opposite of serializing, converting an JSON string to an Object

DeserializeJson<T>(string text) - uses Newtonsoft.Json to deserialize non-Il2Cpp objects

LoadFromFile<T>(string filePath) - same as above, but uses a file stored locally for input instead

Il2CppDeserializeJson<T>(string text) - uses Unity's JSON Deserialization thingy to deserialize some Il2Cpp Objects. Only official supports MonoBehaviour and ScriptableObject subclasses as well as plain structs and classes.

Il2CppLoadFromFile<T>(string filePath) - Il2Cpp version of LoadFromFile