how to add a key in an object array in javascript code example

Example 1: map add key to object in array javascript

const newArr = [
  {name: 'eve'},
  {name: 'john'},
  {name: 'jane'}
].map(v => ({...v, isActive: true}))

Example 2: js array to object with keys

const arr = ['a','b','c'];
const res = arr.reduce((a,b)=> (a[b]='',a),{});
console.log(res)