Issue with serializing circular references

[codersjj]

Here’s the MDN documentation link: Issue with serializing circular references

When we have an array with circular references, and pass it to JSON.stringify(), it works without any issues. For example:

const arr = [];
arr.self = arr;
try {
  JSON.stringify(arr);
} catch (error) {
  console.error("Failed to stringify arr:", error);
}

The code above runs sucessfully without throwing any errors or exceptions.
But since arrays are also objects, why does JSON.stringify() work with circular references in arrays? Could someone explain why this happens? 😄

[caugner]

When serializing an array, properties on the array are ignored, so in your case the empty array is serialized as [], so the self-reference causes no issues, see: https://developer.mozilla.org/en-US/play?id=vSKVZUPzRAXKbEAHdrKm1tRhxnGvKg9CFup9xvCCdz3%2BNRh8QLmsooBoxHvEAYRGlaFWGp3Xkq0U3QRO

[codersjj]

Thanks! @caugner as you mentioned, only array indices between 0 and length - 1 (inclusive) are serialized; other properties are ignored. I also found the description in the MDN documentation.