How to traverse an asynchronous array in JS

Generally, array traversal is carried out in sequence. If asynchrony is involved in the data, the position of the data in the array is not so important. Usually, redcue and PROMISE can be used to solve the traversal problem of the asynchronous array

There is an array like this:

const make = (n, duration) = > new Promise(() = > setTimeout(() = > console.log(n), duration))

let arr = [make(5.1000), make(7.500), make(2.100), make(1.600), make(8.800)]
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Timer length output

arr.forEach(v => v.then(console.log.bind))
=>  2 -> 7 -> 1 -> 8 -> 5
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Order of the output

arr.reduce((p, v) = > p.then(() = > v.then(console.log)), Promise.resolve())
5 -> 7 -> 2 -> 1 -> 8
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