How transform object that contain arrays in keys to array of string with certain field?-CodePudding

I just have object, that contains arrays in keys, and I need get array of string with name property. I cope to do it with flat, but probably there is better solution

const testObj = {
 first: [ { name: 'Den' }, { name: 'Ben' } ],
 second: [ { name: 'Ken} ]
}

Expected result:

['Den', 'Ben', 'Ken' ]

My solution:

const res = Object.keys(testObj).map(key=>{
  return testObj[key].map(el=>el.name)
}).flat(1)

CodePudding user response：

You can use flatMap instead of calling map and flat separately. Also you can replace Object.keys with Object.values

const testObj = {
    first: [ { name: 'Den' }, { name: 'Ben' } ],
    second: [ { name: 'Ken'} ]
}

const res = Object.values(testObj).flatMap(val => val.map(el => el.name))

console.log(res)

If you can't use flatMap, you can flatten the array using Array.prototype.concat:

const testObj = {
    first: [ { name: 'Den' }, { name: 'Ben' } ],
    second: [ { name: 'Ken'} ]
}

const res = [].concat.apply([], Object.values(testObj).map(val => val.map(el => el.name)));

console.log(res)

CodePudding user response：

This looks efficient...

const testObj = {
    first: [ { name: 'Den' }, { name: 'Ben' } ],
    second: [ { name: 'Ken'} ]
}
let sol = [];
Object.values(testObj).forEach( list => list.forEach( el => sol.push(el.name)))
console.log(sol);