Replace array in nested object in Javascript

I have spent a good part of the day trying to replace arrays of an existing nested object but I can’t figure out how to do it. This is my original object:

{
  "id": "a8df1653-238a-4f23-fe42-345c5d928b34",
  "webSections": {
    "id": "x58654a9-283b-4fa6-8466-3f7534783f8",
    "sections": [
      {
        "id": "92d7e428-4a5b-4f7e-bc7d-b761ca018922",
        "title": "Websites",
        "questions": [
          { 
            id: 'dee6e3a6-f207-f3db-921e-32a0b745557', 
            text: 'Website questions', 
            items: Array(11)
         }
        ]
      },
      {
        "id": "79e42d88-7dd0-4f70-b6b4-dea4b4a64ef3",
        "title": "Blogs",
        "questions": [
          ...
        ]
      },
      {
        "id": "439ded88-d7ed0-de70-b6b4-dea4b4a64e840",
        "title": "App questions",
        "questions": [
          ...
        ]
      }
    ]
}

I would like replace the question arrays in the original object or in a copy of it.

const newMenu = [
{id: '34bb96c7-1eda-4f10-8acf-e6486296f4dd', text: 'Website questions', items: Array(24)},
{id: '520c2d3f-6117-4f6a-904f-2477e3347472', text: 'Blog questions', item: Array(7)},
{id: '302b658a-9d8c-4f53-80f6-3f2275bfble', title: 'App questions', items: Array(14)}
]

I am trying to do this by its index but unfortunately it doesn’t work.

 webSections.sections.forEach((item, index) => {
   return webSections.sections[index].questions, newMenu[index]);
 }

Does anyone see what am I doing wrong?

Answer

The value returned from the callback passed to forEach will not be used anywhere.

If you want to avoid mutating the original object and update questions, you can use Array.prototype.map and object spread syntax.

const object = {
  "id": "a8df1653-238a-4f23-fe42-345c5d928b34",
  "webSections": {
    "id": "x58654a9-283b-4fa6-8466-3f7534783f8",
    "sections": [
      {
        "id": "92d7e428-4a5b-4f7e-bc7d-b761ca018922",
        "title": "Websites",
        "questions": [
          { 
            id: 'dee6e3a6-f207-f3db-921e-32a0b745557', 
            ...

const updatedObject = {
 ...object,
 webSections: {
  ...object.webSections,
  sections: object.webSections.sections.map((section, index) => ({...section, questions: newMenu[index]}))
 }
}

If you just want to mutate the original object

object.webSections.sections.forEach((_, index) => {
 section.questions = newMenu[index]
})