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I am trying to create a Promise.all with an array of items. So if I create it like this it works fine
Promise.all([ Query.getStuff(items[0]), Query.getStuff(items[1]) ]).then(result => console.log(result)) If I try to create the Promise.all like this, it doesn't work
Promise.all([ items.map(item => Query.getStuff(item)) ]).then(result => console.log(result)) The then block is run before the Query.getStuff(item). What am I missing?
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An array is a data structure, which can store a fixed-size collection of elements of the same data type. An array is used to store a collection of data, but it is often more useful to think of an array as a collection of variables of the same type.
An array is a collection of similar types of data. For example, if we want to store the names of 100 people then we can create an array of the string type that can store 100 names. String[] array = new String[100];
The purpose of an array is to store multiple pieces of data of the same type together.
You should be writing
Promise.all(items.map(...)) instead of
Promise.all([ items.map(...) ]) Array#map returns an array, which means that the way you wrote your code originally, you were actually passing a multidimensional array to Promise.all — as in [ [promise1, promise2, ...] ] — instead of the expected one-dimensional version [promise1, promise2, ...].
Promise.all( items.map(item => Query.getStuff(item)) ).then(result => console.log(result)) If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
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