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Javascript – Immediate promise chain not executing as expected?

function foo(num) {
  return new Promise((resolve) => console.log(num));
}

foo(1).then(() => {
  foo(3);
});

The function foo returns an immediately resolve promise. "1" is printed, but why doesn’t the chain continue with printing "3"?

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2

Answers


  1. 0

    You need to resolve Promise like this:

    function foo(num) {
  return new Promise((resolve) => {
    console.log(num)
    resolve()
  });
}

foo(1).then(() => {
  foo(3);
});
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  2. 0

    @JobHunter69 The function foo indeed creates a promise but does not explicitly call resolve() to resolve the promise. Therefore, the promise returned by foo never completes or resolves.

    function foo(num) {
  return new Promise((resolve) => {
    console.log(num);
    resolve(); 
  });
}

foo(1).then(() => {
  return foo(3);
}).then(() => {
  console.log("Chain continued successfully.");
});
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