storuky

// С рекурсией (медленно)
const calcSum = list => list.reduce((acc, val) => acc + val, 0);

const cumulativeSum = (list, acc = []) => {
  if (!list.length) return acc;
  
  const sum = calcSum(list),
        subset = list.slice(0, list.length - 1);
  
  return cumulativeSum(subset, [sum, ...acc]);

storuky

const obj1 = {
  field: {
    key: "foo"
  }
};

const obj2 = {
  field: obj1.field
}

storuky

const store = {
  namespaced: true,
  state: {
    users: [],
    posts: []
  },
  mutations: {
    set(state, { name, data }) {
      state[name] = data;
    },

storuky

<template>
<div>
  <form @submit.prevent="addUser">
    <input type="text" v-model="form.name" />
    <button type="submit">Add user</button>
  </form>
  <ul>
    <li :key="user.id" v-for="user in users">{{user.name}}</li>
  </ul>
</div>

storuky

// Original data
{
  "data": {
    "level1": {
      "field1": "data 1 on level 1", // changed
      "level2": {
        "field1": "data 1 on level 2",
        "level3": {
          "field1": "data 1 on level 3", //changed
          "field2": "data 2 on level 3"