Different Json fields

Hi, I have a question related to Json.

My code loops through every item in the json file:

My question though is how do I add for example a weapon that has differrent fields from the fields shown above. For example I want to add a weapon with the "implicit" being "implicit": {"damage": 5, ...}", however since the items with id: 0 and id: 1 don't have the damage field, I will get this error:

Any work-around for this? Thanks!