I am using nodejs with jsonpath. I have this json structure:
{
things:{
books: [
{name: "book1"},
{name: "book2"},
{name: "book3"},
{name: "book4"},
],
movies: [
{name: "movie1"},
{name: "movie2"},
{name: "movie3"},
{name: "movie4"},
]
}
}
I would like to know the jsonpath expression that returns an array with the key names of the things object. That would be:
["books","movies"]
For now, I am doing this:
Object.keys(jsonpath.eval(jsonStructure,"$.things").pop());
But I don't find it elegant... I should not need to get a copy the whole structure when I only need the key names.
I don't believe there is a better solution than your own:
Object.keys(jsonpath.eval(jsonStructure,"$.things").pop());
I think the main misconception here is that you don't have to worry about this snippet "getting a copy of the whole structure", because you aren't copying the whole structure. You already have the entire object loaded into memory, jsonpath doesn't create a new copy, it simply returns a reference to the already existing object, i.e.:
jsonpath.eval(jsonStructure,"$.things").pop() === jsonStructure.things //true