414032 - Large integers (2^55) become different values when written as strings

Status: RESOLVED INVALID

(Core :: JavaScript Engine, defect)

Description

[Vidar Holen]

User-Agent:       Mozilla/5.0 (compatible; Konqueror/3.5; Linux; X11; x86_64) KHTML/3.5.7 (like Gecko)
Build Identifier: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.8.1.11) Gecko/20080125 Firefox/2.0.0.11

document.write(36028797018963968) writes 36028797018963970  (off by two). Larger integers result in larger errors.


Reproducible: Always

Steps to Reproduce:
1. Put <script>document.write(36028797018963968)</script> on some web page
Actual Results:  
Writes 36028797018963970

Expected Results:  
Should write 36028797018963968

This happens with MSIE and Opera as well, but not Konqueror. Some kind of ES issue?

Comment 1

[Jeff Walden [:Waldo]]

Yes; numbers in ES3 are floating-point doubles with 52 (53 with the hidden bit, I believe) bits of precision.  Your number is large enough that the imprecision is visible at the integer level; for smaller numbers the difference is less than 1.