map 值到 object 内的数组

Question

I have this object below

{
  "root": {
    "data": {
      "page": 1,
        "contents": [
          {
            "node": {
              "id": "UzpfSTE",
              "stats": {
                "viewers": {
                  "nodes": [
                    {
                      "id": "1",
                      "name": "John"
                    },
                    {
                      "id": "2",
                      "name": "Shaun"
                    }
                  ]
                }
              }
            }
          },
          {
            "node": {
              "id": "UzpfSTG",
              "stats": {
                "viewers": {
                  "nodes": [
                    {
                      "id": "3",
                      "name": "Liam"
                    }
                  ]
                }
              }
            }
          }
        ]
    }
  }
}

There is contents node, each of them will have many viewers, all I want is to extract all viewers name to an array, in this instance my result will be [John, Shaun, Liam]

I have this approach:

const data = JSON.parse(rt)

const contents = data.root.data.contents
const newArray = []

for (i = 0; i < contents.length; i++) {
  arr2 = contents[i].node.stats.viewers.nodes
  for (n = 0; n < arr2.length; n++) {
    name = arr2[n].name
    newArray.push(name)
  }
}

console.log(newArray)
>>> [John, Shaun, Liam]

Which does the job, but occasionaly the object key names change and I have to alter everytime.

So is there more elegant way to do this?

Answer 1

You can simplify that imperative logic like this. I don't understand what you mean by "the object key names change" though

 const data = { "root": { "data": { "page": 1, "contents": [{ "node": { "id": "UzpfSTE", "stats": { "viewers": { "nodes": [{ "id": "1", "name": "John" }, { "id": "2", "name": "Shaun" } ] } } } }, { "node": { "id": "UzpfSTG", "stats": { "viewers": { "nodes": [{ "id": "3", "name": "Liam" }] } } } } ] } } } const names = data.root.data.contents.flatMap(({ node: { stats: { viewers: { nodes } } } }) => nodes.map(({ name }) => name)) console.log(names)

Answer 2

const data = JSON.parse(rt) const contents = data.root.data.contents const viewers = contents.map(item => item.node.stats.viewers.nodes).flat() const viewerNames = viewers.map(viewer => viewer.name)