Answers for "get all js specific object values in arr"

get array of all property in object array

objArray = [ { foo: 1, bar: 2}, { foo: 3, bar: 4}, { foo: 5, bar: 6} ];
let result = objArray.map(a => a.foo); //[1,3,5]
//OR
let result = objArray.map(({ foo }) => foo) //[1,3,5]

object get array of values

const data = {
    "2015": {
        "year": 2015,
        "cover": {}
    }
}

Object.entries(data).forEach(([key, value]) => console.log(key, value));