Why is 9999999999999999 converted to 10000000000000000 in JavaScript?

Question

Can any one explain to me why 9999999999999999 is converted to 10000000000000000?

alert(9999999999999999); //10000000000000000

http://jsfid

Answer 1

Javascript doesn't have integers, only 64-bit floats - and you've ran out of floating-point precision.

See similar issue in Java: why is the Double.parseDouble making 9999999999999999 to 10000000000000000?