Using async-await

serial-parallel-async.js

const axios = require('axios');

const empIds = ['72632', '72633', '72634'];
const dummyRESTurl = 'http://dummy.restapiexample.com/api/v1/employee/';
const result = [];

//Serial
(async () => {
    for (let i = 0; i < empIds.length; i++) {
        const body = await axios.get(`${dummyRESTurl}${empIds[i]}`);
        result.push(body.data);
    }
    console.log(result);
})()

//Parallel
const promises = [];
empIds.forEach((empID) => {
    promises.push(axios.get(`${dummyRESTurl}${empID}`));
});
(async () => {
    const pResult = await Promise.all(promises);
    console.log(pResult.map(r => r.data))
})();