JSFiddle - React, Tailwind, and code Playground
JavaScript
var countries = {
China: 1371980000,
India: 1276860000,
'United States': 321786000,
Indonesia: 255461700,
Brazil: 204873000,
Pakistan: 190860000
};
var countriesFiltered = {};
Object.keys(countries).filter(function(key) {
return countries[key] <= 1000000000;
}).map(function(key) {
countriesFiltered[key] = countries[key];
});
console.log(countriesFiltered);