Introduction A colleague of mine and I have been discussing the asynchronous nature of JavaScript in the browser and wondering what technical benefits are. We are aware that async/await is syntactical sugar for Promises, but curious to know if there is any other performance benefit for using one over the othe…
Tag: asynchronous
wait for asynchronous functions to finish in Angular
So I was working on a new component in Angular and in the ngOninit I have the following asynchronous functions below… This.getUserProfile needs to be finished before I can call this.getPrivateGroup() and this.getPrivateGroup() needs to be finished before I can call this.loadGroupPosts(). I know I could …
How to execute multiple mongoose queries asynchronously and wait until all of them finish executing before sending response?
Thanks in advance, but could someone explain to me how can I execute a different query for each property of my request? I am trying to create a search sidebar menu, when user changes checkbox values I create an object with these properties: I want to push a query into an array of functions and then execute th…
Promises returned data ”
my data which is fetched from youtube is using nodejs is – Now I want to search 5 related videos to each video my api and api to 5 related Videos is given below It is giving the output like How to solve this pending problem or how to wait so it gets full data. Answer It happens because you
Implementation of Promise.race()
I came across an implementation of the Promise.race() method in JavaScript, which works as expected, but doesn’t make much sense to me. How does the forEach loop end up assigning a specific promise’s functions? Answer By definition a promise resolves / rejects only once, no matter how often you ca…
how to chain async methods
The API I’ve written has several async methods that do not return a value, but still should be executed in the order they are called. I’d like to abstract the awaiting resolution from the end user so that they can chain method calls and expect that each promise is executed after the previous is re…
Error using async and await with filereader
I’m trying to read a file using FileReader: However, evt.target.result still gets printed after my console.log(file) call. Does anyone know how I can obtain the result of the file and pass it to my processFileContent function? Answer Use the new read methods on the blob itself Alternative:
Async Concurrent Queue with max concurrency
I’m running across a bug with a custom asynchronous queue that calls 10 async functions at a time. I’m initiating the queue with 50 jobs, once first 10 jobs are finished the queue moves to the subsequent 10 until it finishes all. The bug I’m coming across is that once it finishes 50, it rest…
why is async-await much slower than promises when running them together
I found out that running async-await can be much slower in some scenarios. IMO, the console.log in usingPromises should print similar results to the one in usingAwait. But in reality, I get: Total (promises): 0.25 ms Total (await): 2.065 ms Also, after the page load, if I click on ‘usingPromises’ …
How to execute AJAX calls in order in loop using Javascript Promise
I am looping through a map, where I want to make a separate AJAX call with each map value as parameter, to fetch some data and log it. See below. This is working, but I’d like to have the AJAX calls go in order of the map. Because each call is asynchronous, so seems like I should use promises to