name an object in Array-CodePudding

I'm doing multiple fetchs with Promise.all. So I receive data like this :

[
   0: {
      ...
   },
   1: {
      ...
   }
]

But I would like to name my Objects. So I can do data.myObject istead of data[0].

I would like the index to be a string that I chose. For example, i'd like to get :

[
   "home": {
      ...
   },
   "product": {
      ...
   }
]

Is is possible ? Thanks

CodePudding user response：

No, this is not possible. Promise.all works on iterables (like arrays), not on objects. Name your values after the Promise.all call:

const data = await Promise.all([…, …]);
const home = data[0], product = data[1];

becomes with destructuring

const [home, product] = await Promise.all([…, …]);

CodePudding user response：

Promise.all works with an array. Arrays deal in numerically indexed (ordered) values.

You'd need to have a name stored somewhere for each promise, and then generate the object from them once the promises had resolved.

e.g.

const names = ['home', 'product'];
const promises = [fetchHome(), fetchProduct()];
const results = await Promise.all(promises);
const resultsByName = names.reduce((prev, curr, index) => {
    return {...prev, [curr]: results[index]};
}, {});

You could use a similar approach without the second array if the name was available in the resolved values of fetchHome() and fetchProduct().

CodePudding user response：

You can destructure the array of Promise results in the Promise.all.

const [home, product, toolbar, nav] = await Promise.all([
getHome(), getProduct(), getToolBar(), getNav()
]);

Since the results are an array like anything else you can destructure arrays and even use the ...rest syntax:

const [home, product, toolbar, nav, ...otherPromises] = await Promise.all([
getHome(), getProduct(), getToolBar(), getNav(), getOtherThing1()
]);
// otherPromises will be an array that you'll have to access
// with numeric keys as before:
// eg. otherPromises[0] might be the first non-named promise
// the result of getOtherThing1()

CodePudding user response：

Seems like you want to convert Array to an object so you can get data by calling a key.

const arr = [ { id: "home", val: "val1" }, { id: "product", val: "val2" }];
const convert = arr.reduce((a,b) => (a[b.id] ??= b,a),{});
console.log(convert);
console.log(convert.home);