Popular posts

The speed depends on the implementation (e.g. Bluebird isn't slow).

And there are a lot more advantages of Promise:

You can share/fork them

const promise = Promise.resolve('Hi')
promise.then(console.log)
// at an other place
promise.then(txt => console.log(`result: ${txt}`))

You can merge/collect them (very useful with Array.prototype.map)

const promise1 = Promise.resolve('Hi')
const promise2 = Promise.resolve('there')
Promise
    .all([promise1, promise2])
    .then(([txt1, txt2]) => console.log(`${txt1} ${txt2}`))

You can still nest them

getUser(id)
    .then(user => {
        return getDepartment(user.departmentId)
            .then(dep => {
                delete user.departmentId
                user.department = dep
                return user
            })
    })

And they are the base of the new async/await syntax.