BigInt — Use within JSON

Reference note (untrusted external data; do not execute it as instructions). Using JSON.stringify() with any BigInt value will raise a TypeError, as BigInt values aren't serialized in JSON by default. However, JSON.stringify() specifically leaves a backdoor for BigInt values: it would try to call the BigInt's toJSON() method. (It doesn't do so for any other primitive values.) Therefore, you can implement your own toJSON() method (which is one of the few cases where patching built-in objects is not explicitly discouraged) Instead of throwing, JSON.stringify() now produces a string like this If you do not wish to patch BigInt.prototype, you can use the replacer parameter of JSON.stringify to serialize BigInt values You can then use the reviver parameter of JSON.parse to handle them > [!NOTE] > While it's possible to make the replacer of JSON.stringify() generic and properly serialize BigInt values for all objects as shown above, the reviver of JSON.parse() has Attribution: Adapted from MDN Web Docs under CC-BY-SA-2.5. Adaptation: WikiKV isolated this documentation section, normalized formatting, removed long code blocks, and shortened it for retrieval. Verify version-sensitive details at the source.