Promise inside forEach loop

Question

I have a API call to update a record in a loop. I want to have a promise around API call so that the next iteration is not called until the first is finished. How can I achieve this?

I have tried this but this gives an error "Can not use keyword 'await' outside an async function"

async saveMyData(){
  this.elements.forEach(element => {
        await this.$refs.DM.saveInternalData(element)
  })
}

The arrow function you pass to `forEach` is a different function to `saveMyData`! — Quentin, Mar 13 '20 at 13:20
You can't use `await` inside a `forEach` callback: you need to use the good old `for` loop instead. — Terry, Mar 13 '20 at 13:21

score 2 · Accepted Answer · answered Mar 13 '20 at 13:21

2

If you want to use an async function in a loop, you can do:

for (let i = 0; i < elements.length; i += 1) {
  await foo();
}

answered Mar 13 '20 at 13:21

Colin Ricardo

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Alternatively you can do: await Promise.all(this.elements.map(this.$refs.DM.saveInternalData)) – Alexandre Nicolas Mar 13 '20 at 13:23

Promise inside forEach loop

1 Answers1