The JSON (JavaScript Object Notation) data interface handles the loss of precision of large numbers due to its reliance on JavaScript's number type, which is a 64-bit floating-point format (IEEE 754 double-precision). This format can accurately represent integers up to 53 bits in length (i.e., up to 9,007,199,254,740,991 or Number.MAX_SAFE_INTEGER). When a number exceeds this limit, it may lose precision because the floating-point representation cannot store all digits exactly.
For example, consider the large integer 9007199254740993. In JavaScript (and thus in JSON), this number might be incorrectly represented or rounded due to precision limitations. If you parse or transmit this number as a plain JSON number, it could be altered without notice. Here's an example:
{
"largeNumber": 9007199254740993
}
When this JSON is parsed in JavaScript, the value of largeNumber might unexpectedly become 9007199254740992, which is incorrect.
To avoid such precision loss, best practices recommend transmitting large numbers as strings in JSON. By representing the number as a string, you preserve the exact digit sequence and avoid any issues related to floating-point inaccuracies. For instance:
{
"largeNumber": "9007199254740993"
}
In this case, the value remains exactly "9007199254740993" when parsed, and applications can interpret it as a string and convert it to a big integer type if necessary (e.g., using BigInt in JavaScript or similar types in other languages).
In cloud-based application development, especially when dealing with APIs that might exchange large numeric identifiers (like database primary keys, transaction IDs, or financial figures), it's common to follow the approach of sending such numbers as strings. Many RESTful APIs and JSON-based data interchange formats adopted by platforms recommend or enforce this pattern.
If you are building services on a cloud platform, such as using serverless functions or API gateways, you can implement logic to ensure large numbers are serialized as strings in JSON responses. Cloud providers often offer tools and managed services to help with API development, data validation, and transformation. For example, you can use cloud-native API management services to automatically handle JSON serialization and ensure that large numbers are formatted as strings to prevent precision issues. Additionally, when storing or processing such data, leveraging cloud databases that support arbitrary-precision numeric types or string fields for large numbers is advisable.