javascript - Parse Float has a rounding limit? How can I fix this?

Question

I set up a system that parses a compact data string into JSON. I'm using a 19 digit number to store ids. Unfortunately any number greater than 17 digits, parseFloat() rounds the last few digits.

This breaks the whole data string. Can I fix this?

For example 8246295522085275215 gets turned into 8246295522085276000. Why is this?

http://jsfiddle.net/RobertWHurst/mhZ7Q/

Answer 1

JavaScript has only one numeric type, which is an IEEE 754 double precision floating-point. That means, you have a maximum of 52 bits of precision, which is a bit more than 15 decimal places.

If you need more precision than that, you have to use a bignum library or work with strings.