CODEWITHSUNDEEP
javascript
hortenzz1
hortenzz1

Reputation: 33

JS: Nesting promise chains or keep them at same scope?

Do these essentially do the same thing? I came across this while in a Promise example and the lecturer had returned the fetch but wouldn't example 1 be another viable way of doing this as well?

1

fetch('url1')
.then(data => data.json())
.then(() => {
    fetch('url2')
    .then((response) => {
       // do things
    })
})

2

fetch('url1')
.then(data => data.json())
.then(() => {
    return fetch('url2')
    
})
.then((response) => {
    // do the same thing but at same scope
});

Upvotes: 0

Views: 25

Answers (1)

Quentin
Quentin

Reputation: 943214

In example 1, the second then() resolves to undefined

In example 2, the second then() adopts the promise returned by the second fetch and so the final then could return something usable at the top level return value.

Either way. It's quite verbose code that could be a lot clearer using async and await.

Upvotes: 1

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