JSON iterieren, aber wie?

[Pfaffe]

Wie lese ich denn das aus?
"length": [
0,
"mm"
].
Sowas verstehe ich:
"important_information": {
"hazard_warnings": null
}
subobj_important_information := (subobj as TJSONObject).Values['important_information'] as TJSONObject;
Memo1.Lines.Add(subobj_important_information.Value s['hazard_warnings'].Value);