FULL PRODUCT VERSION :
java version "1.8.0_144"
Java(TM) SE Runtime Environment (build 1.8.0_144-b01)
Java HotSpot(TM) 64-Bit Server VM (build 25.144-b01, mixed mode)

ADDITIONAL OS VERSION INFORMATION :
Darwin xx 16.7.0 Darwin Kernel Version 16.7.0: Thu Jun 15 17:36:27 PDT 2017; root:xnu-3789.70.16~2/RELEASE_X86_64 x86_64

A DESCRIPTION OF THE PROBLEM :
jrunscript

var a = new java.io.File("/bin/cat");

print(typeof a.length()); // object
print(a.length() == a.length()); // false

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
jrunscript

var a = new java.io.File("/bin/cat");

print(typeof a.length()); // object
print(a.length() == a.length()); // false

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
number
true
ACTUAL -
object
false

REPRODUCIBILITY :
This bug can be reproduced always.