let cities = [
    {name: 'Los Angeles', population: 3792621},
    {name: 'New York', population: 8175133},
    {name: 'Chicago', population: 2695598},
    {name: 'Houston', population: 2099451},
    {name: 'Philadelphia', population: 1526006}
];

let bigCities = cities.filter(city => city.population > 3000000);
console.log(bigCities);

/* ES5
let bigCities = cities.filter(function (e) {
    return e.population > 3000000;
});
*/

Code language: JavaScript (javascript)