promises-with-map.js

const promiseWithMilliseconds = (ms, index) => {
    return new Promise((resolve,reject) => {
        console.time(`Time:${index}`)
        setTimeout(() => {
            console.timeEnd(`Time:${index}`)
            return resolve(`Resolved in ${ms}`)
        }, ms);
    })
}

const delays = [1000,2000,3000,4000]

const promisesToCall = delays.map((delay, index)=> {
    return promiseWithMilliseconds(delay, index)
})

Promise.all(promisesToCall)
 .then((result) => {
   console.log('Result', result)
 })
 .catch((error) => console.log(`Error: ${error}`))


/*
  Time:0: 1003.169921875 ms
  Time:0: 1.005s
  Time:1: 2003.0888671875 ms
  Time:1: 2.004s
  Time:2: 3000.85205078125 ms
  Time:2: 3.001s
  Time:3: 4001.341064453125 ms
  Time:3: 4.002s
  Result (4) ['Resolved in 1000', 'Resolved in 2000', 'Resolved in 3000', 'Resolved in 4000']
*/