Combine two nested json objects with javascript and loop through it with a key

Question

I have a few json objects (obj1,obj2...) and each is taken from.txt files:

{
  "countries": [
    {
      "Country name": "China",
      "Flag": "CN",
      "Population": 1395380000,
      "undefined": "#688144"
    }, ... ]}

and

{
  "countries": [
    {
      "Country name": "India",
      "Flag": "IN",
      "Population": 1338677000,
      "undefined": "#B78A31"
    }, ...]}

And so on. Now I want to combine them like this:

{
  "countries": [
    {
      "Country name": "China",
      "Flag": "CN",
      "Population": 1395380000,
      "undefined": "#688144"
    },
 {
      "Country name": "India",
      "Flag": "IN",
      "Population": 1338677000,
      "undefined": "#B78A31"
    },
 ... ]}

So I can loop through data like this:

let obj1 = {}; //saved Data From Txt1;
let obj2 = {}; //saved Data From Txt2
...
let obj = combined?

for (var key in obj.countries) {
var num1 = obj.countries[key].Population+popholder;
if (target >= popholder && target <= num1) {
  var country = obj.countries[key]['Country name'];
  var testas = document.getElementById("countryname")
}}

How could I achieve this?

Answer 1

Just concat the arrays:

 const obj1 = { "countries": [{ "Country name": "China", "Flag": "CN", "Population": 1395380000, "undefined": "#688144" } ] }; const obj2 = { "countries": [{ "Country name": "India", "Flag": "IN", "Population": 1338677000, "undefined": "#B78A31" } ] }; const result = { countries: [...obj1.countries, ...obj2.countries] }; console.log(result);

Answer 2

You can use create a new object with the same countries properties and use Array#concat to combine all the arrays of countries into one:

 const obj1 = { "countries": [{ "Country name": "China", "Flag": "CN", "Population": 1395380000, "undefined": "#688144" }, /*... */ ] }; const obj2 = { "countries": [{ "Country name": "India", "Flag": "IN", "Population": 1338677000, "undefined": "#B78A31" }, /*... */ ] }; const obj3 = { "countries": [{ "Country name": "Sealand", "Flag": "", "Population": 27, "undefined": "#0000FF" }, /*... */ ] }; const combined = { countries: [].concat( obj1.countries, obj2.countries, obj3.countries ) }; console.log(combined);

If you have an array of the objects, you can combine Array#map with spread syntax to extract the countries arrays and combine them into one:

 const obj1 = { "countries": [{ "Country name": "China", "Flag": "CN", "Population": 1395380000, "undefined": "#688144" }, /*... */ ]}; const obj2 = { "countries": [{ "Country name": "India", "Flag": "IN", "Population": 1338677000, "undefined": "#B78A31" }, /*... */ ]}; const obj3 = { "countries": [{ "Country name": "Sealand", "Flag": "", "Population": 27, "undefined": "#0000FF" }, /*... */ ]}; const objArr = [obj1, obj2, obj3]; const combined = { combined: [].concat(...objArr.map(x => x.countries) ) }; console.log(combined)

Answer 3

You can push all of the arrays into one.

 const obj1 = { "countries": [ { "Country name": "China", "Flag": "CN", "Population": 1395380000, "undefined": "#688144" }, ]} const obj2 = { "countries": [ { "Country name": "India", "Flag": "IN", "Population": 1338677000, "undefined": "#B78A31" },]}; const res = [obj1, obj2, /*...*/].reduce((acc,{countries})=>(acc.countries.push(...countries),acc), {countries: []}); console.log(res);