flatten js object to Depth = 1

flatten-object.js

let oldData = {
  age: 3,
  name: "dudeson",
  height: 70,
  type: 3,
  address: {
    city: 'Manila',
    street: 'street 66',
    province: {
      district: {
        number: 'IV',
        name: 'Nueva Ecija'
      }
    }
  },
  this_shit: [3,3,4 ,4]
}

const flattenObject = (obj) => {
  let flattened = {}
  Object.keys(obj).forEach((key) => {
    // perform recursion if this is the case
    if (typeof obj[key] === 'object' && !Array.isArray(obj[key]) && obj[key] !== null) {
      let flat = flattenObject(obj[key])
      Object.keys(flat).forEach((innerKey) => {
        flattened[`${key} -> ${innerKey}`] = flat[innerKey]
      })
    } 
    else { // exit recursion here
      flattened[key] = typeof(obj[key]) === 'string' ? obj[key] : JSON.stringify(obj[key])
    }
  })
  return flattened
}

console.log(flattenObject(oldData))