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JavaScript Manage Multiple Requests with Promise.all

Posted by Rushabha Jain
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Rushabha Jain
Full Stack JavaScript Techdegree Student 11,140 Points

Promise.all()?

Whether promises are executed parallely/sequentially?

1 Answer

Brendan Whiting
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Brendan Whiting
Front End Web Development Techdegree Graduate 84,735 Points
Brendan Whiting
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Brendan Whiting
Front End Web Development Techdegree Graduate 84,735 Points

JavaScript is single threaded, so only one thing is happening at a time. But, we can still have concurrency. We can send off an http request and move on to something else while we're waiting for the response. When you use Promise.all(), you fire off an array of promises, so you can have multiple requests in flight at the same time, and that could have the effect of having work done on different servers at the same time. But as far as your JavaScript program itself, it's not parallel but it can use concurrency which is usually what we're aiming for here.