7 replies

anonn – 15-18 Oct 10

Hi, I have trouble understanding how promises work in terms of the event loop.

function a() {
    console.log('a')
}

function b() {
  console.log("b");
}

function c() {
  console.log("c")
}

fetch("https://fakelinkabcabc.com").catch(a);

Promise.resolve().then(b);

Promise.reject().catch(c);

function a() {
    console.log('a')
}

function b() {
  console.log("b");
}

function c() {
  console.log("c")
}

fetch("https://fakelinkabcabc.com").catch(a);

Promise.resolve().then(b);

Promise.reject().catch(c);

Why is the output b,c,a

Could someone explain in terms of the event loop? e.g the image attached

What actually happens when the javascript engine reaches Promise.resolve()Promise.resolve()? What actually happens when the .then(b).then(b) is reached?

I have been unable to find resources that go through step by step how interacting with Promises/Web APIs work in terms of the event loop and would be very happy if someone could point me some resources

Reactiflux•4y ago•

7 replies

anonn

anonn – 15-18 Oct 10

Hi, I have trouble understanding how promises work in terms of the event loop.

function a() {
    console.log('a')
}

function b() {
  console.log("b");
}

function c() {
  console.log("c")
}

fetch("https://fakelinkabcabc.com").catch(a);

Promise.resolve().then(b);

Promise.reject().catch(c);

function a() {
    console.log('a')
}

function b() {
  console.log("b");
}

function c() {
  console.log("c")
}

fetch("https://fakelinkabcabc.com").catch(a);

Promise.resolve().then(b);

Promise.reject().catch(c);

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