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Promise allSettled vs Promise all

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By Lam Ngoc Khuong
views 1 min read

Promise all

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Promise.all([
    Promise.reject('✗'),
    Promise.reject('✗'),
    Promise.resolve('✓'),
    Promise.reject('✗'),
]).catch((err) => {
     console.log('You win at life', err);
})

Promise all will reject as soon as there is a Promise in the Array returned to reject.

Result:

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You win at life ✗

Promise allSettled

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Promise.allSettled([
    Promise.reject('✗'),
    Promise.reject('✗'),
    Promise.resolve('✓'),
    Promise.reject('✗'),
]).then(function(value) {
    console.log(`You win at life`, value)
})

Promise allSettled will run all Promises in the array, regardless of whether they return rejected or fulfilled

Result:

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You win at life,
[
    {
        status:"rejected",
        reason:"✗"
    },
    {
        status:"rejected",
        reason:"✗"
    },
    {
        status:"fulfilled",
        value:"✓"
    },
    {
        status:"rejected",
        reason:"✗"
    }
]
Javascript
javascript promise
This post is licensed under CC BY 4.0 by the author.